38
Report PHOSPHENE IMAGES OF THALAMIC SLEEP RHYTHMS INDUCED BY SELF-HYPNOSIS by Philip T. Nicholson ABSTRACT A medical writer describes internally-generated light sensations (phosphenes) induced by a technique of self-hypnosis that combines relaxation, convergent eye movement, and attentive fixation. The phosphene images include: (1) a threshold sequence of receding annuli, (2) amorphous phosphene mists or clouds, and (3) phosphene clouds with two levels of brightness and color saturation. These images share some similarities with visions of light reported by religious mystics. Based on an analysis of the distinctive spatiotemporal characteristics exhibited by the phosphenes. the author proposes the hypothesis that they are generated by thalamic sleep rhythms oscillating in the lateral geniculate nucleus (LGN). Since humans usually lose conscious- ness at the onset of non-rapid-eye-movement sleep (NREMS), the author also proposes the hypothesis that his technique of phosphene induction preserves consciousness, despite the operation of thalamic sleep rhythms, because eye movements and attentive fixation send excita- tory feedback to the visual pathways. This selective facilitation of visual neurons appears to preserve their signal-processing capacity even though synchronous sleep rhythms may be installed in the non-visual thalamus. The author speculates that this selective disruption of sleep rhythm activity in the visual pathways may be the mechanism that produces the cutaneous analgesia (hypnoanalgesia) he experiences when he induces phosphenes. KEYWORDS: Attention, brain rhythms, eye movements, hypnosis, phosphenes, sleep, thalamus, vision Subtle Energies & Energy Medicine Volume 7 • Number 2 Page 111

PHOSPHENE IMAGES OF THALAMIC SLEEP RHYTHMS INDUCED BY …

  • Upload
    others

  • View
    3

  • Download
    0

Embed Size (px)

Citation preview

Report

PHOSPHENE IMAGES OF THALAMIC SLEEP RHYTHMS INDUCED BY SELF-HYPNOSIS

by Philip T Nicholson

ABSTRACT

A medical writer describes internally-generated light sensations (phosphenes) induced by a technique of self-hypnosis that combines relaxation convergent eye movement and attentive fixation The phosphene images include (1) a threshold sequence of receding annuli (2) amorphous phosphene mists or clouds and (3) phosphene clouds with two levels of brightness and color saturation These images share some similarities with visions of light reported by religious mystics Based on an analysis of the distinctive spatiotemporal characteristics exhibited by the phosphenes the author proposes the hypothesis that they are generated by thalamic sleep rhythms oscillating in the lateral geniculate nucleus (LGN) Since humans usually lose consciousshyness at the onset of non-rapid-eye-movement sleep (NREMS) the author also proposes the hypothesis that his technique of phosphene induction preserves consciousness despite the operation of thalamic sleep rhythms because eye movements and attentive fixation send excitashytory feedback to the visual pathways This selective facilitation of visual neurons appears to preserve their signal-processing capacity even though synchronous sleep rhythms may be installed in the non-visual thalamus The author speculates that this selective disruption of sleep rhythm activity in the visual pathways may be the mechanism that produces the cutaneous analgesia (hypnoanalgesia) he experiences when he induces phosphenes

KEYWORDS Attention brain rhythms eye movements hypnosis phosphenes sleep thalamus vision

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 111

INTRODUCTION

To understand the mechanisms involved in the exercise of voluntary control over mental processes it is important to learn more about how different kinds of attention affect local brain networks I This paper

describes how the authors manipulations of spatial attention during a relaxed immobile expectant state induce light sensations in the absence of an external light source (phosphenes) The endogenous mechanisms that produce this effect can be identified ad hoc by analyzing the spatiotemporal characteristics of these phosphenes

A recent study suggests that an unexpectedly large number of people will selfshyinduce phosphenes during relaxed immobile expectancy 2 After telling 28 subjects they would be exposed to an extremely-low-frequency electromagnetic field the researchers only simulated their usual protocol without actually activating any electromagnetism Despite the absence of an external stimulus 90 of their subjects reported seeing phosphenes mostly colored moving phosphenes (73) The researchers concluded that phosphene reports associshyated with exposures to electrical or electromagnetic fields did not warrant further investigation on the grounds that the psychological component of the perception of electric and magnetic phosphenes must not be underestimated However their finding raises another question one the researchers themselves do not ask but which will be the focus of our investigation Why do so many subjects report seeing phosphenes while waiting in a state of immobile expectancy If these subjects did in fact see phosphenes what endogenous mechanisms might account for this phenomenon

In a recent positron emission tomography (PET) study of mental visualization subjects were asked to rest in a state of relaxed immobile expectancy while the researchers took measurements of brain metabolism for a baseline resting condition3 They assumed this state would generate only minimal levels of neuronal activity in the visual cortex and thus would serve as a good base for comparison with brain metabolism during the performance of assigned tasks The instructions (adopted from an earlier PET study4) were as follows subjects were asked to remain (1) supine (2) motionless (3) blindfolded with their eyes closed (4) not to say anything to tense their muscles or to change respiratory rhythms after inhalation of the tracer and (4) to have it

Subtle Energies amp Energy Medicine bull Volume 7 bull Numher 2 bull Page 112

black in front of their minds eye (ie not to have any visual imagery)3-4 A cortical EEG confirmed that all subjects had predominant alpha-rhythm as is expected when subjects are relaxed with eyes closed When they analyzed the results the Kosslyn team was surprised to find that the baseline resting condition generated a significant increase in neuronal activiry in the primary visual cortex an increase that antedated the performance of the assigned visual tasks The similarities berween the behaviors used as the baseline resting condition in the PET studies and the behaviors used by the author to induce phosphenes suggests that similar mechanisms may be involved In this paper we hope to identifY those mechanisms

METHODS

The author a fifty-year-old medical writer with no history of drug or alcohol abuse uses autohypnosis to disperse pain during dental or medical procedures to relieve muscle tension headaches to warm his extremities

and to induce sleep His method of autohypnotic induction resembles the generic relaxation response popularized by Benson but involves a more active manipushylation of eye position and attention 5 To begin inducing phosphenes the author lies on his back closes his eyes takes slow deep rhythmic breaths and gives himself silent instructions used in autogenic training such as let yourself relax or concentrate on the breathing6 If body or mind resists relaxing he tries progressive relaxation techniques which involve tensing and relaxing the large muscles of the body in systematic sequence

Once noticeable relaxation is present the author begins to manipulate eye position to accelerate dissociation He converges his eyes with enough force to elicit a continuing sensation of fullness or pressure in the eyeball At the same time he tests which of rwo different eye positions produces the strongest feeling of having the attention hone in or lock in on the fixation point at the center of vision (1) with eyes converged and slightly depressed as if focusing on the tip of the nose or (2) with eyes converged and elevated as if focusing on the forehead or crown If the eyes were opened in either of these positions they would produce a non-fused image of the external world (With long practice the response is conditioned so that a less forceful convershygence is needed to produce the same effect)

Subtle Energies 6- Energy Medicine bull VoLume 7 bull Number 2 bull Page 113

I n addition to manipulating eye position the author focuses all his attention on the fixation point at the center of the visual field even though at this early stage in the phosphene induction process the visual field remains

empty of everything except random metabolic discharge referred from the retina-the eigengrau or self-generated gray light When the attention is fixated strongly enough the author experiences auditory feedback-a distincshytive tinnitis cerebri that seems part sound but also part vibration This sensation originates inside the lower rim of the skull at about the level of the ears and feels as if it radiates upward on both sides It sounds like bird wings fluttering the sputtering of an open wood fire or a dull buzz The reader can experiment with eliciting a version of this same tinnitis by staring intently at some external object located just beyond the reach of an extended arm With practice this tinnitis can be sustained for long intervals and used as a feedback signal to mark the efficiency of dissociation Long practice also conditions this response so that a slight convergence of the eyes a straight-forward stare and fixed attention are sufficient to evoke the tinnitis and then the phosphenes The author continues the stereotyped eye movements and attentive fixation until phosphenes appear and for the duration of the phosphene displays

No less important than sustained convergence and attentive fixation is the ability to keep the level of arousal low and the mental field free of distractions The author remains passive and ready to acquiesce in whatever happens To minimize the distraction of unwanted thoughts images emotions itches or pains he uses a traditional meditation strategy-not attempting to resist distracting content but rather treating its arrival with indifference letting it drift freely in and out of consciousness This disengagement from potentially disruptive thoughts combined with steady breathing and the intense focusing of attention preserves equanimity and maintains a low level of arousal

Pain control requires adding another strategy In response to a painful stimulus the large muscles of the body usually tense involuntarily and fear of further pain breaks into awareness The author counters these instinctive and involunshytary reactions by deliberately posing the thought that the pain is not actually attached to the body that the pain can be given away by allowing it to flow out of the body and to disperse in all directions in which case the author need not take action in order to escape or avoid the pain This mental strategyshyin effect a deliberate abandonment of the normal vigilance which is oriented

Subtle Energies amp EnerfJ Medicine bull Volume 7 bull Number 2 bull Page 114

toward behaviorally significant external stimuli-results in a sudden preCIpIshytous drop in tension and restoration of the former relaxed state This reshyrelaxation occurs immediately after the muscles tense involuntary in response to the painful stimuli Keeping relaxed helps diffuse the pain sensations and the anxiety about pain The anticipation that relaxation (and the relief it brings) can be quickly restored after the next painful stimulation creates confidence that events are not out of control and that therefore it is not necessary to divert ones attention from the focus on the visual field that generates the phosphenes

The authors phosphene induction method closely resembles the behaviors used as the baseline resting condition in the PET studies except that in those studies subjects were not explicitly instructed to converge their eyes or to fixate their attention However the authors attempt to carry out their instructions-lying motionless with eyes closed and having it black in front of the minds eye results in his eyes focusing automatically on the near visual field an operation which requires some convergence (although not as much as the author would normally use) His attention also focuses automatically on the center of the empty visual field If the authors experience is typical then the two sets of behaviors may be virtually the same with differences being in degree not in kind

OBSERVATIONS

PHOSPHENE RECEDING ANNULI

The threshold sequence of phosphene images is illustrated in Figure 1 Just before the appearance of phosphene there is a fleeting sensation of a movement inward from 3600 of the peripheral visual field (VF)

as if a dark annular wave were moving through the dark background with so little contrast that it is almost imperceptible This annular wave suddenly illuminates while still in the far periphery of the VF (at about 80 - 60deg of isoeccentricity) presenting a bright thin phosphene annulus yellow-green in color that decreases in diameter at a constant rate preserving its annular symmetry until it disappears into the centerpoint after 4 seconds of elapsed time (estimated by counting 1001 1002 etc) There is an interval

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 115

0- 05 sec 10 sec 15 sec

20 sec 25 sec 30 sec

Figure 1 Schematic drawings ofreceding annuli phosphenes At first there is a sensation of movement inward from 360 0 in the periphery of vision then a bright thin yellowshygreen phosphene annulus sudden~y illuminates at about 80 60 of isoeccentricity The edges ofthe annulus are well-defined but more diJfose than this computer drawing program can depict-like a wellformed smoke ring The annulus preserves its symmetry as it shrinks steadio in diameter at a constant rafe offlow creating the illusion that it is receding toward the center of vision At 2 seconds the empty space inside the annulus fills abrupto with a disk ofbrighter phosphene At 4 seconds the image disappears into the centerpoint At 5 seconds another annulus sweeps into the periphery The author sees a total of4 receding annuli

of 1 second then the next wave appears at the periphery of the VE Midway in the trajectory-at 2 seconds-the empty interior of the annulus fills abruptly with a disk of slightly brighter phosphene A sequence of annuli usually terminates after 4 images although the number of annuli can be increased by diverting the attention for a moment and then refocusing

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 116

While the color of the annulus has remained the same over time the color of the filling-in disk changed after about two years of intermittent phosphene induction from yellow-green to blue The change began with tiny flecks of blue flashing amid the green just as the disk disappeared Over a period of several weeks the amount of blue expanded and appeared earlier in the fillshysequence Within a month the entire fill-disk was blue

The shrinking annuli create a psychological illusion of a ring of light receding toward a distant point in 3-dimensional space and pulling the attention into a vortex or paradoxically the same progression can create a sensation of falling backwards an illusory motion that resembles an effect produced by optic flow Motion in the visual periphery elicits in the stationary observer an illusion of self-motion (vection) indistinguishable from real motion The illusion of vection is compelling for it dominates contradictory proprioceptive signals For example subjects presented with optic flow consistent with backward self-motion perceive backward motion even if they ate actually walking forward 8

T he same receding annuli appear spontaneously as hypnagogic images while the author is reclining and waiting for sleep The receding annuli appear whenever the authors mind and body are relaxed his eyes closed

and his attention focused straight ahead-essentially the same behaviors used for self-hypnosis-but in the hypnagogic context virtually no effort is required the receding annuli feel as if they were released spontaneously not induced If the author is not relaxed or if he is distracted by a headache or importuning thoughts then the luminous receding annuli do not appear Instead the author loses consciousness abruptly at the onset of NREMS

AMORPHOUS EXPANDING PHOSPHENES

(A) loCAL RANDOMLY-DISPERSED EXPANDING WAVES Figure 2(A) illustrates one kind of amorphous phosphene mist that appears after the receding annuli sequence terminates These phosphenes are small amorphous swirls of yellowshygreen that coalesce suddenly at unpredictable locations in the VF and expand for a second or two then fade into the background There are often several images drifting in the visual field at the same time each in a different stage of evolution and the density of the phosphene seems to vary with some areas appearing thin and translucent others more opaque-like puffs of smoke that

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 117

10 seconds 15 sec 20 sec

25 Bee 30 sec 35 sec

expand and curl aimlessly then dissipate Because these waves are so unpredictable and formless the author is unable to predict the mean number of signals per episode the period between signals the site of entry or exit or to define a typical trajectory other than in the abstract generic manner used above The signal-to-noise ratio in these phosphenes is very low since phosphene stands out against the background there clearly is a signal but this signal presents so little pattern that it is essentially a form of phosphene noise These localized pulsations may continue for several minutes but usually within a minute or two they are superceded by the type of amorphous wave described next

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 118

Figure 2 [focing page Schematic drawings of of amorphous expanding phosphenes (A) Brief randomly-dispersed localized pulses These phosphenes are the first to appear after the receding annuli They coalesce at unpredictable locations in the IF expand asymmetrically for a second or two then dissipate into eigengrau before there is time to extend very for beyond their locus of origin (B) Periodic unidirectional amorphous expanding waves These phosphene waves enter the periphery ofvision from one hemifield presenting as a loosely-defined crescent (hemi-annular) cloud that mirrors the curvature of the peripheral rim The leading edge of the wave expands and flows across the vertical meridian into the opposite hemified swirling around the periphery curling inward and merging while at the same time the trailing edge ofphosphene dissipates rapidly in those regions over which the wave has already passed like mist or smoke evaporating in air The author is unable to time these waves but their duration fiels roughly the same as for receding annuli ie about 4 seconds Waves appear one after another in a cluster with a refractory period between clusters during which no waves appear After a prolonged session ofself-hypnosis the phosphene may not completely dissipate between successive waves in which case the residual phosphene accumulates in a vaguely-circular cloud shape with a small area its center that undergoes continual perturbation the phosphene pulls back leaving a small Mrk circle at the center of the cloud then fills back in then pulls away again ebbing and flowing in like manner until the cloud dissipates At this stage the image resembles an eye with a phosphene iris and a dark inner pupil (C) Twoshytone phosphene During a prolonged session the phosphene at the very center of the amorphous cloud becomes much brighter more fine-grained almost opaque with highly saturated color When a hole (pupil) appears in the center ofthe cloud forming an eyeshyimage the brighter phosphene becomes a thin bright rim lining the Mrk hole from this bright inner rim tiny promontories ofbright phosphene flare out into the Mrk hole twist and coil and collide with other flares forming webs and momentarily filling-in the Mrk hole or receding back into the rim The two-toned phosphene does not only appear in conjunction with the eye-shape clouds it also manifests at the center ofa variety ofelusive ever-changing shapes It is always restricted to the area offoveal vision

(B) PERIODIC UNIDIRECTIONAL AMORPHOUS WAVES These phosphene waves sweep in from one hemifield as shown in Figure 2(B) Often the wave has a vaguely crescent shape at the outset that conforms to the concave curvature of the peripheral VF then the crescent shape gives way as the wave expands rapidly in divergent directions flowing smoothly across the vertical meridian to envelop those regions of the VF that have not yet been illuminated As the leading edge of the wave expands the rear edges are already beginning to dissipate The swirling movement and the contraction of outer boundaries leaves a cloud of phosphene near the center of the VE This cloud may dissipate rapidly or it may persist for several seconds during which a pertur-

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 119

bation takes place at the center of the cloud the phosphene ebbs away from this region leaving a tiny dark hole then the phosphene fills back in then it ebbs and fills again-a fluctuation that continues as long as the phosphene cloud is visible During the perturbations the phosphene vaguely resembles the iris of a human eye with an interior dark space as its pupil This eyeshyimage is seldom symmetrical and its boundaries are always changing

(c) TWO-TONE PHOSPHENE When the phosphenes are induced over a prolonged period of time the phosphene in the central region representing foveal vision presents a more intensely bright more opaque (finely-grained) character than the rest of the cloud as shown in Figure 2(C) When this brilliant opaque phosphene appears as part of an eye-image it forms a thin rim surrounding the pupiL From this rim flares jut out into the dark pupil space coil about merge or recede back into the rim

The periodic unidirectional amorphous waves do not terminate after a stereoshytyped sequence they can be evoked over prolonged rime periods if the autohypshynotic behaviors are maintained The author is unable to retain the vision of these amorphous waves while simultaneously counting the number of seconds elapsed it is his impression however that the duration of amorphous expanding waves feels about the same as for receding annuli that is a duration of about 4 seconds per wave The amorphous waves usually appear in clusters followed by a refractory interval during which no phosphenes appear even if induction behaviors are sustained

PHOSPHENES SUPERIMPOSED ON ExTERNAL OBJECTS

The author can observe amorphous phosphene images with his eyes open if he is in a room dark enough that colors cannot be distinguished or if he is

in a lighted room but one where he can keep his eyes diffusely focused on a relatively undifferentiated surface such as a wall or ceiling with a light and uniform color and no distracting decorative adornments In open-eye viewings phosphenes appear as faint translucent waves of yellow-green mist

superimposed over the surface or in the dark space that fills the darkened room If the author attempts to focus on the features of external objects the phosphenes disappear

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 120

RECEDING ANNuLI EVOKED BY MAGNETIC REsONANCE IMAGING (MRI)

A s a patient undergoing an MRI scan the author observed an unusual sequence of receding annuli He was not relaxed as in a normal induction but rather anxious about his medical condition and about

being confined in the narrow MRI tube To keep calm he concentrated on breathing slowly and stared straight ahead While the sound of MRI machine was audible the author observed a stream of receding annuli that differed from the usual sequence (self-induced and hypnagogic) in three ways (I) the MRI annuli did not terminate at 4 cycles but continued for as long as the author kept his attention focused (2) the MRI annuli were only yellowshygreen in color even though in other inductions the fill-in disk had already changed from green to blue and (3) MRI annuli completed their trajectoshyries in half the normal time disappearing in 2 seconds instead of 4 An interval of 2 seconds between radio pulses is often selected as optimal interval for capture of the signals emitted by hyperexcited atoms in the subjects body

10during the precessional relaxation 9- These observations suggest that energy released in the wake of the radio bombardment during MRI moves through the LGN as a standing wave in the same way that spindle bursts move but that the 2-second duration of the MRI wave is not long enough to activate the neurons that generate a blue sensation

THE ANESTHETIC EFFECT ASSOCIATED WITH SELF-INDUCED

PHOSPHENES

On several occasions the author has preferred to undergo minor surgery without local anesthetic and to rely instead on autohypnotic analgesia-for example during extraction of an infected abscess from the back during laser surgery to

remove keloids and during the filllng of dental caries His experience on a recent occasion when a dentist had to abrade the surface of six teeth with damaged enamel in order to create a strong bonding surface are worth describing here because the experience implies that spindle waves can be induced even during a state of high physiological arousal For this appointshyment the author arrived in the office too late to hypnotize himself in advance

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 121

so he had to begin the normal induction procedures after the dental work was already underway

A s the dentist worked on the first tooth the author experienced apprehension sharp sensations of pain and an involuntary tensing of the large muscles of the body with each application of the drill As

the author kept his eyes converged and his attention focused on the center of the visual field the involuntary tensing in response to pain alternated with a precipitous relaxing of those same muscles immediately after the stimulus With the repeated relaxation came a sense of relief and of letting go that amelioshyrated the pain The pain-driven relaxation was much stronger than the relaxation that normally accompanies the authors self-induction of phosphenes and the alternation of a pain-driven tensing on one hand and the distancing effect of focusing attention on the visual field on the other hand resulted in a rapid dissociation from all external and internal stimuli including a signifishycant amelioration of painful sensations

Most striking is the fact that by the time the dentist reached the third toothshyafter only a few minutes of this pain-driven self-hypnosis-the author saw a normal sequence of 4 receding annuli followed by swirling clouds of amorphous expanding phosphene even though the dentist was still using the drill contemporaneously This experience suggests that thalamic sleep rhythms can be voluntarily induced even when the subjects level of physiological arousal is high

SIMILARITIES WITH ATTENTION-INDUCED PHOSPHENES

REpORTED BY OTHER OBSERVERS

Taxonomies of phosphene images always include examples of simple geometric phosphenes with circular or semi-circular shapes (disks annuli or crescents) as

14well as formless phosphene mists 11 - There are also a number of anecdotal accounts that are relevant for example Friedman an opthamologist who studied entoptic images by introspection describes a similar sequence of annuli induced by sustained inward concentration Circular waves of blue color may be seen in the dark by the dark adapted retina They start at the

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 122

periphery and move inward toward the macula as a concentrically contracting solid circle disappear at the macula and begin again at the peripheryl)

A valuable but often-neglected resource of information about phosphene imagery is presented in the literature of religious mysticism Many mystics reported having seen translucent colored lights while absorbed in prayer or meditation A list of descriptions excerpted from self-reports is presented in Table 1 (These excerpts are representative of phosphene images that appear during states of calm and inward-oriented concentration they do not include images associated with paroxysmal raptures) These phosphene images exhibit a relatively limited set of shapes and colors the shapes are either circular (eg rings disks wheels suns) or formless (eg mists snow smoke) and the colors are usually a variant of either green or blue The phosphene visions of mystics display shapes and colors that are comparable to the images described by the author this and the many similarities in the behaviors used to induce phosphenes suggest that both sets of phosphenes have a common etiology

DISCUSSION

Whether the author uses self-hypnosis to induce phosphenes or experishyences them as hypnagogic images the threshold sequence of receding annuli has the same characteristics In both these

instances the antecedent behaviors involve a state of low physiological arousal combined with mental withdrawal from external stimuli These parallels suggest the hypothesis that phosphene displays are related to sleep-wake transitions

PART I RECEDING ANNULI AND THALAMIC SPINDLES

Mechanisms controlling the transition from waking to NREMS Based on the work of several research teams16-20 a consensus scenario for the generation of NREMS has emerged In this scenario NREMS is the product of three brain rhythms that interact with each other in thalamocorticothalamic circuits During the drowsy transition to sleep which in humans is called stage l NREMS the low voltage activity in the cortical electroencephalograph (EEG) still shows a pattern of intermittent desynchronization The polarization of

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 123

Table I Excerpts from self-reports of light visions by religious mystics

HEBREW MYSTICS the appearance of the wheels was like the gleaming of beryl and the four had the same form

their construction being something like a wheel within a wheel Ezekiel like a dome shining like crystal spread out about their heads And above the dome something

like a rhrone in appearance like sapphire Ezekiel a round Iodder like a full sphere rolling back and forth before him bright blue R Abulafia A glowing light clear brilliance A purple light that absorbs all lights R Moses de Leon

HINDU AND BUDDHIST MYSTICS a perfectly round beautiful deep-blue shape of a size appropriate to the center of a mandala as

if exquisitely painted of extreme c14rity Tsong Khapa a luminous revolving disc studded with lights a lotus flower in full bloom Gopi Krishna both my eyes became cemered When this happened a blue light arose in my eyes like

a candle flame without a wick and stood motionless in the ajna chakra S Muktananda

MUSLIM MYSTICS [like] chandelierssublime lights [like] stars moon or the sun Sharafuddin aI-Maneri its color is deep blue it seems to be an upsurge like water foom a spring Najmoddin Kobra visualize yourself as lying at the bottom of a well [looking up at the light of the opening] and

the well in lively downward movement Najmoddin Kobra the color green is the suprasensory uniting all the suprasensories Alaoddawleh Semnani the light rises in the Sky of the hean taking the form of light-gilling moons Najm Razi

CHRISTIAN MYSTICS his own state at prayer resembles a sapphire it is as clear and bright as the sky Evagrius descending like a bright cloud of mist like a sun round as a circle Simeon Neotheologos saw something in the air near him He did not understand the rype of thing but in some ways

it appeared to have the form of a serpent with many things that shone like eyes although they were not eyes Ignatius of Loyola

the soul puts on a green amilia [cape worn on shoulders beneath armor] John of the Cross [the almilla is like a helmet which] coverS all the senses of the head of the soul It has one

hole rhrough which the eyes may look upwards John of the Cross a round thing about rhe size of a rixdaier all bright and clear with light like a crystal H Hayen I saw a bright light and in this light the figure of a man the color of sapphireblazing with a

gentle glowing fire the three were in one light Hildegard von Bingen saw a b14zing fire incomprehensible inextinguishable with a flame in it the color of the sky

Hildegard von Bingen saw placed beneath her fuet the whole machine of the world as if it were a wheel She saw herself phced

above it her eyes of contemplation magnetized towards the incomprehensible Beatrice of Nazareth I saw the eyes I do not know if I was asleep or awake Angela of Foligno kind of sunlit winged being like a childs head beneath two little wings Abbess Thaisia laquobullbull round patterns small circles would expand and eventually dissipate only to be followed by other small

circles of light Philip St Romain an extraordinary circle of gold light pulsating against a deep violet background There were

always four or fille As soon as one would fode another would appear Philip St Romain

middotItalics added to mark words referring to (l) rings appearing in sets of four (2) amorphous shapes such as clouds or flames (3) circular or eye-like shapes (4) colors from the center of the visible spectrum (gold yellow yellow-green green bluish green) and (5) colors from the lower end of rhe visible spectrum (blue purple violet)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 124

cell membranes (Vm) has already begun to drop (hyperpolarize) in the thalamic reticular nucleus (RTN) a thin sheath of GABAnergic inhibitory neurons that acts as a pacemaker When the Vm of RTN cell membranes drops to approximately V m -60 millivolts (mV) RTN cells stop firing single spikes which are associated with waking states and instead begin firing highshyamplitude 7-14 Hertz (Hz) spike-bursts These bursts wax and wane over 1 to 3 seconds-hence the name spindle -and recur at 3 to 10 seconds Spindle volleys are relayed across the cortical mantle by thalamocortical (TC) sensory relay cells In human studies the primary criterion for onset of the first fullyshyestablished episode of NREMS or stage 2 sleep is the presence of globalized spindles in the cortical EEG

When spindle bursts from the RTN stimulate TC cells to fire in synchrony this synchronous bursting pattern overwhelms the normal capacity of TC cells to relay afferent sensory signals The loss of consciousness at the onset of stage 2 NREMS is thought to be caused by this blocking effect 21

While the RTN is firing spindle bursts through the thalamus another process is activated in the cortex large numbers of cells across the cortical mantle begin to oscillate at a very low frequency laquo 1 Hz)

The cortical slow rhythm referred back to the thalamus via corticothalamic circuits intensifies the hyperpolarizing effect of the RTN spindle bursts on TC cell membranes When V m -75 mV the TC cells begin to generate their own intrinsic calcium currents which further increases hyperpolarization At V m -90 mV the RTN neurons stop firing spindle bursts The TC cells continue to fire low-threshold calcium spikes in patterns which are controlled by the cortical slow rhythm The interaction of these two oscillations generates the delta waves (1 to 4 Hz) which are associated with stage 2 NREMS

In a study of sleep rhythms using the cortical EEG Uchida Atsumi and Kojima found that the mean number of spindles required to induce delta wave activity (that is to induce Vm = -90 mY) is 478 plusmn 162 spindles (from 3 to 7 spindles)22 The mean number of spindles in a volley remains the same for a single individual over multiple trials

Based on the consensus scenario for generation of NREMS we can predict that a phosphene image generated as an epiphenomenon of a thalamic spindle

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 125

Table II Dara show rhe degree of correspondance berween rhe pulse panerns of rhalamic spindles based on intracellular research and rhe sparioremporal panerns of receding annuli phosphenes induced by rhe author using a rechnique of self-hypnosis

Receding annuli phosphenes Thalamic spindle bursrs

Mean number of signals 4 annuli 487 (plusmn 16) bursrs

Sparial exrension vs Thin band 1 - 3 seconds durarion of signal ( 05 -15 cm)

Periodicity of signals 5 seconds 3 - 10 seconds

Simultaneity in LGNs Yes Yes

Point of entry Peripheral VF Ventral amp lareral LGN

Trajecrory Bilareral concentric Unknown

Rare of flow Cons rant rare Unknown

Signal-ro-noise rario High High (shorr bursrs) (sharp brighr discrere)

Termination of sequence Mrer 4 signals Mrer 487 (plusmn 16) signals

will present the following characteristics (1) a high-definition burst-like signal (2) that recurs within 3 to 10 seconds (3) that follows a trajectory compatible with having entered the LGN from the RTN (4) that has a predictable mean for the individual subject and a range that falls somewhere between 2 to 7 annuli and (5) that the spindles will terminate automatically

The temporal patterns of receding annuli and thalamic spindle bursts are similar Table II illustrates the close match between the timing of receding annuli phosphenes and thalamic spindle bursts The most striking similarities are the mean number of signals required to induce termination (4 annuli versus 487 spindles) and the interval between signals (5 seconds for annuli versus 3shyto-lO seconds for spindle bursts) Neither alpha theta nor beta waves present this kind of stereotyped temporal pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 126

T he spatial features of receding annuli are functions of geniculate anatomy A spindle burst moving through the LGN to the cortex will acquire certain distinctive spatiotemporal characteristics because of the

unique curvilinear and laminar anatomy of the LGN A drawing of a macaque LGN based on a clay model constructed by Le Gros Clark23 is shown in Figure 3 The primate LGN is composed of six sheets of cells or laminae that fold over a central hylus In macaques the hylus rises steeply as it extends rostrocausally forming a high arch at the posterior pole in humans the hylus is much more shallow but the functional anatomy is thought to be essentially

23 24the same in both cases - The geometry of the arch forces each lamina to bend so as to constitute in effect one-half of a conical surface and each lamina with its hemi-conical shape contains visual relay cells representing the contralatshyeral half of the visual field (VF) Operating as a pair the complementary hemishycones of the right and left LGN form the functional equivalent of a single conical surface which represents the entire VE This conical geometry of the paired LGNs means a burst of otherwise formless excitation will acquire a distinctive shape as it propagates through the laminae of the LGN Imagine a horizontal section moving along the surface of a cone from base to apex that moving section forms an annulus that shrinks in diameter as it approaches the apex but retains its annular symmetry throughout its trajectory

Figure 3 also includes drawings that show how Connolly and Van Essen24

converted the 3-dimensional structure of lamina 6 the largest and most dorsal layer into a 2-dimensional map Connolly and Van Essen used data obtained by Malpelli and Baker25 to superimpose a grid that specifies the areas in lamina 6 that contain TC cells representing various degrees of isoeccentricity in the VE We will use this map at a later point to show how the movement of a spindle wave through a pair of LGNs correlates with what appears in the VE

The location of the RTN relative to the LGN is also shown in Figure 3 The RTN spindle pacemaker is a thin sheath of GABAnergic inhibitory cells that extends along the surface of the whole posterior ventral thalamus not just the LGN This extension brings the RTN into close proximity with the portion of the LGN (lateral wing) that protrudes out from the main body of the thalamus Some of RTN wraps around and beneath the ventral edges of the LGN26 The RTN comes closest to the LGN in two areas along the ventral edges of the longest laminae (lamina 6 and 1) and along the edge of the lateral

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 127

DORSAL POLE DORSALPOIEA B

L1 L4 L3 L

DORSAL POlE DORSAL POIE (FOVEA)

G LATERAL WING

25

DORSAL POL (FOVEA)

10 _DIAL

20 WING

~

wing These areas contain TC cells that represent the far periphery of the VE If a spindle burst enters the LGN at locations where laminae are in closest proximity to the RTN-along the ventral edges-then the discharge of TC cells will begin in the most ventral portions of the laminae the regions that represent the far periphery of the VE This matches the phosphene sequence observed by the author

Our hypothesis about how this proximity between RTN and LGN affects the trajectory of spindle waves is illustrated in Figure 4 We propose that it is not possible for the author to observe a thin annulus of phosphene sweeping in from all 3600 of the peripheral VF unless spindle bursts exhibit the following

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 128

Figure 3 [facing page Drawings of primate geniculate anatomy and functional anatomy relevant to the generation ofphosphenes (A) Anterior view ofa macaque monkey LGN based on a clay model reconstruction by Le Gros Clark 23 (B) Posterior view ofthe same model showing 6 laminae folded over a central hylus to form lateral and medial wings with the hylus arching steeply upward near the posterior pole to shape the laminae into layers of hollow half-cones nested together Note that the lateral wing of the LGN is slightly larger than the medial wing so that in situ the lateral wing protrudes out from the main body of the thalamus creating a small knob visible during dissection 26 (C) Schematic drawing of an oblique section through median axis (also adapted from Le Gros Clark13 showing how the laminae fuse together at the anterior pole The afferent ganglion cell axons that form the optic tract (OT) penetrate through the anterior surface to reach their target relay cells in the laminae (D) Drawing of the most dorsal lamina-layer 6--separated from the rest of the LGN The geometric shape is a hollow half-cone so that right and left LGNs placed back-to-back form in effect a single cone Note also the position ofthe RTN shown here as a striped bar relative to lamina 6 The position of the striped bar shows that the RTN makes direct contact with lamina 6 at the edge ofthe lateral wing and also along the ventral edges (E - F) Schematic drawings adapted from Connolly and Van Essen24 that show how a 3-dimensional lamina-lamina 6--can be transformed into a 2-dimensional triangular figure lamina 6 is removed and its wings unfolded (E) creating a slightly asymmetric triangular figure (F) which is adjusted to an oblong shape (G) in order to superimshypose a grid matrix with minimal distortion The grid plots locations of TC cells that represent various isoelevations and isoazimuths in the VF locations derived from the experimental observations published by Malpeli and Baker 25 Note the relatively large amounts of laminar surface allocated to central vision (0 0

- 30 0) as compared

to peripheral vision (30 0 - 80 0)

characteristics (1) Spindle bursts must move simultaneously through both geniculate nuclei This pattern of movement is consistent with anatomical studies in primates that found axonal projections linking the right and left RTNs27-28 and with experimental studies in cats that found spindles appearing simultaneously in both right and left thalami 29 (2) Spindle waves must enter the ventral edges of the LGN first and move ventrodorsally in a highly coherent pattern-moving in effect as a standing wave This pattern of movement is consistent with in vitro experiments using sagittal slices from a ferret LGN where spindle waves originated spontaneously at the edge of a slice in an area which contains cells that represent peripheral vision then propagated toward that area of the slice containing cells that represent central vision in the ferret 3o

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 129

VF

PG BIlateral receptive lleJd of PVN YI(j Inward dmKooflality Adapled

0-- from Mortgr at at (1987)

V1

ibull t bull

RTN t t t t t t 1middot3 SECOlO BURSTS OF 7middot14 HZ SPiKES RECURRNG EVERY 3 10 SECONDS

To our knowledge the LGN is the only anatomical structure in the visual system that has the capacity of passively forcing a wave of excitation to flow across a conical surface thereby generating the sensation of a phosphene annulus that retains its symmetry as it shrinks in diameter The retina has a circular anatomy but it is not likely that the mechanical deformation of the retina would produce a wave that began simultaneously in all 3600 of the retinal rim nor that the symmetry of annular wave would be preserved as it flows inward toward the foveal region

The hypothesis presented here-that there is a structure in the visual system that imprints a conical shape on standing waves that move through it-explains

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 130

Figure 4 facing page Schematic drawing of contemporaneous events in selected regions of the visual processing hierarchy (A) The left and right RTNs fire spindle bursts simultaneously (B) The bursts pass through the right and left geniculate laminae as standing waves of depolarization entering from the ventral edges and moving ventrodorsally in parallel In order for the phosphene annulus to appear to be flowing at a constant rate the spindle wave flowing through the LCN must expand in width as it ascends ventrodorsally so that by the time the fill-in disk appears-when the center 30deg of the VF is covered by the phosphene annulus-the spindle wave must have expanded enough to activate relay cells in the most dorsal 50 of lamina 6 (C) Signals representing two complementary hemi-annuli are kept separate in the primary visual cortices (area VI) (D) Signals representing the two hemi-annuli are integrated into signals of a single annulus when they reach area PC in the posterior parietal cortex where the receptive fields of single parietal visual neurons have the capacity to register bilateral signals that exhibit opponent vector movement (that is signals converging from opposite directions along the central axes-as if an object were moving away from the viewer)46 Neurons in area PC also integrate wavelength (color) signals from the extrastriate visual pathway with signals about brightness motion and depth from the parietal visual pathway to compose a representation of an object in space-in this case of an annulus that appears to recede 32

the authors experience during MRI when he observed a continuous succession of receding annuli every 2 seconds in this view the energy of the electroshymagnetic bombardment when released during precessional relaxation flows through the geniculate laminae in the same way that the RTN spindle bursts do that is as a standing wave and thus the visual epiphenomenon is the same in both cases if the subject keeps the eyes focused straight ahead and the attention fixated In a study of phosphenes evoked by electricity in conjunction with hallucinogenic drugs Knoll Kugler Hofer and Lawder found that each subject sees specific kinds of phosphene at different frequencies and that these frequency-specific images are stable enough to be reproduced after six months31

They conclude that the tunability of the electrical stimulation frequenshycies within the EEG range to various definable phosphenes requires the existence of a resonance system One mechanism contributing to that resonance system may be the functional anatomy of the LGN

The colors of receding annuli as functions of geniculate laminar anatomy The colors of receding annuli phosphenes are consistent with the patterns of discharge spindle waves can be expected to stimulate as they move through

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 131

geniculate laminae As shown in Figure 5 the six laminae differ (1) in the types of wavelength signals relayed (2) in physical size and (3) in the area of the VF represented 24-25 Only 4 out of 6 laminae Cparvocellular layers 3shy6) contain TC cells that relay wavelength signals the other 2 laminae (magnocellular layers 1 and 2) do not encode wavelength Among parvocelshylular laminae only lamina 6 the longest and most dorsal layer contains TC cells that can represent the far periphery of the VF (from 800 to 50deg of isoeccenshytdeity) therefore when the spindle wave enters the peripheral VF only those wavelengths relayed by lamina 6 will participate in composing a cortical lightness record (See Zeki)32

I n lamina 6 ganglion cell axons arriving from the retina carry two kinds of wavelength signals (1) center-ON signals from medium-wavelength cones (M-cone center-ON) and long-wavelength cones (L-cone centershy

ON)33-35 Using the cone spectral sensitivity curves (adapted from Marks et al 36) we average the wavelengths that elicit maximal responses for M-cones (535 nanometers) and L-cones (520 nm) which yields a mean wavelength value of 550 nm In humans this wavelength generates a sensation of green or yellowshygreen the sensation observed by the author

As the spindle burst moves ventrodorsally it reaches the dorsal areas in the geniculate laminae which contain TC cells representing the central 0deg to 20deg of isoeccentrieity in the VE All 4 parvocellular laminae have TC cells which are potentially capable of representing this central region of vision but the authors observation that the color of the filling-in disk changed from green to blue implies that in the early years of phosphene induction the spindle wave must have remained close to the surface of the LGN stimulating only laminae 5 and 6 which generates a sensation of yellow-green When the fill-in disk was observed to change color from green to blue the spindle wave must have been rechanneled so that it began to penetrate below laminae 5 and 6 and to activate laminae 3 and 4 the only laminae that relay blue-sensitive signals (Sshycone center-ON signals)3 In light of the authors MRI experience it seems likely that a spindle wave requires a minimum of 2 seconds to reach the blueshysensitive cells of laminae 4 therefore during MRI when the receding annuli disappeared after 2 seconds half the normal duration the fill-disk had a green color even though it had long since change to blue in other induction settings with a 4-second trajectory

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 132

A REPRESENTATION OF THE VISUAL FIELD IN EACH LAMINA

orooqUtftc O-u OCIJ1SALfIOLI (I01flAj

0

10

20

30

40 n50 Of

60

70

20 loO 1Mgr_ II~ o UIpoundAS65 mn1MY-o actlvncL ~~~r

Jll-COMcetlImiddot~

II LAYERSU 3 GatQYancetl~ (1) ucon ceom-oyenF (2)l~cen()FF 3) ~ cenloH

II~ cng1loqctWIIIfNla

iICINe -- (t81Otdb1t1d~OH (2)~

80

B CONE SPECTRAL SENSITIVITY CURVES

S-COHS

WAVIlLllNG1llS OF UGHT IH NANOMllTERS (NM)

Figure 5 Phosphene color as a function of ganglion cell distribution in parvocellular laminae (Aj Schematic drawing ofthe proportion ofthe VF represented in each laminae The proportions shown here are based on the work of Connolly and Van Essen24 The

far periphery of vision (50 0 to 80 0 of isoeccentricity) is represented in only two laminae-laminae 1 and 6-and of these two only lamina 6 is a parvocelLular lamina capable ofencoding wavelength signals Therefore only those wavelengths relayed by lamina 6 will participate in forming a cortical lighmess record for the far periphery of the VP (B) Cone spectral sensitivity curves (adapted from Marks et al)36 Using these cone sensitivity curves we can estimate the sensation stimulated by a spindle wave moving through lamina 6 by averaging the wavelengths that elicit maximal responses for M-cones (535 nanomeshyters) and L-cones (520 nm) which yields a mean wavelength value of550 nm In humans this generates a sensation of green or yellow-green the sensation observed by the author when the receding annulus enters at the far periphery of the VP For a calculation of the cortical lightness record when a spindle wave moves through 20deg to 0deg ofthe VF stimulating all 4 parvocelfular laminae see the text and Figure 6

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 133

Once the spindle wave penetrates to laminae 3 and 4 it may activate all 4 parvocellular laminae stimulating TC cells to send contradictory wavelength signals for the same retinotopic location the signals sent from laminae 4 and 3 will encode blue light (S-cone center-ON plus M-cone center-OFF and Lshycone center-OFF) while the signals sent from laminae 5 and 6 encode yellowshygreen light (M-cone center-ON plus L-cone center-ON) This kind of contrashydiction does not occur in normal retina-based perception where light energy striking the retina is structured by the retinas center-surround and colorshyopponent organization to encode only one set of wavelength signals for each spatial locus 32 In Figure 6 we estimate the cortical lightness record that results when contradictory wavelength signals compete to be represented in consciousshyness Our calculations suggest that the outcome will be a mean wavelength which in humans elicits a dark blue or violet sensation

PART II AMORPHOUS PHOSPHENES amp THALAMIC DELTA ACTMTY

M echanisms controlling the transition from spindle bursts to delta activity In the consensus scenario for the generation of NREMS16-20 we noted that the RTN shifts to firing spindle bursts

when polarization of thalamic cell membranes drops to V m = - 60 mV At the same time cortical cells begin oscillating with a synchronous slow rhythm laquo 1 Hz) Both processes further decrease the Vm of TC cell membranes When Vm = - 75 mY TC cells begin to generate their own intrinsic calcium currents which also decreases V m At V m = - 90 mV RTN neurons stop firing spindle bursts At the same time the TC cells begin firing low-threshold calcium spikes in alternation with after-hyperpolarizations (LTS-AHP) Because sensory relay neurons in the LGN are not linked to one another by locally projecting axons the firing of one TC cell does not excite its neighbor However a lack of local connectivity does not mean that TC cells occupying the same laminae release their AHP-LTS calcium spikes in a random distribshyution rather spikes are released simultaneously by groups of cells in synchrony with the advent of the cortical slow wave In effect the distribution of LTSshyAHP spikes firing in the LGN is determined by the spatial propagation of the cortical slow wave Thus the delta wave (1 to 4 Hz) activity detected by cortical EEG during NREMS is a product of the interaction between the AHP-LTS calcium spikes released by TC cells and the cortical slow rhythm

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 134

CORTICAL PROCESSING OF CONTRADICTORY

WAVELENGTH SIGNALS

KEY _ Cells firing

cJ Cononol firing

Assume that as a spind6e wave moves through the LGNlt fires simultaneously aU the TC cells that represent a particular reUnoshytopic locus (x y) in each of the six laminae As a result cortical cells engaged In the higher level processing of visual signals will receive more wavelength signals representing retina locus (x y) than are generated by normal perception laquo and some of these afferent wavelength signals may contradict other signals arriving simultaneously

CORTICAL LIGHTNESS RECORD SlgnalSell

Intemal contradictions not congruent wilt pre

SmiddotON eristing neuron neta

s bullbull M-ON LmiddotON

3 bullbull M-OFF + L-OFF

a-ON 12

ROD-ON

No Internal eonlradlemiddot

--------1I =~8b~~~~~~~t signals

3+4

~ --OFF Excludes 6 Of 7 $J9n18

1+2 B-ON I

IWmiddotHmiddotI Signal Sell

1111111 No Intern1 conlrfldlcshy lion

Exelvdta 4 out of 7 efshy

bullbullbull bullbullbull ferant signals

No Intern1 contradic_ tionnee S-ON BshyOH and ROO-ON can all be coacllve at low lImlnance levels nef Ihe rod-eone break

ExchJde$ only 2 Ollt of 7 afferent signals

Figure 6 Selection of competing wavelength signals based on neuronal group selection This thought experiment is based on Edelman sconcept ofneuronal group selection 73 We assume that all possible combinations ofsignals will form sets and that all signal-sets will compete to make the most efficient match with pre-existing neuromd networks that have been forged over years ofnorma reti1U1-based perception We also assume that pre-existing neural networks are most likely to expedite those sets that satisfY 2 criteriI (J) the signals in a set do not contradict each other and (2) fower signals are excluded than in the other sets that satisfY the first criterion In our analysis Set 4 wins the competition because it does not contain internal contradictions and excludes fower signals (2 out of 7) than Set 3 excludes (4 out of7) It is not an internal contradiction that Set 4 contains both rods and cone Signtlls in normal retina-based perception when luminance levels approach the rod-cone break S-cone center-ON receptors send signas as do rod receptors and there is even evidence that rod activity may actually drive S-cone activity even after luminance levels foIl below the rod-cone break74 To calculate the cortical lightness record for Set 4 we average the wavelength that elicits maximal responses foom rods (511 nm) and for Sshycones (430 nm) which yields a mean wavelength of 470 nm which in humans results in a dark-blue or violet sensation

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 135

The cortical slow rhythm is an example of a generic pattern of neuronal excitashytion that occurs in large networks of neurons linked by local projections A recent experiment by Maeda Robinson and Kwana38 shows that networks of locally-connected neurons spontaneously generate periodic synchronized bursts of calcium transients that propagate across the network in an expanding spatial wave a pattern that represents a stable mode of firing towards which these neuronal networks relax following perturbations for example by electronic stimulation or by drugs Understanding the characteristics of these waves is an important prerequisite to understanding the mechanisms that produce the amorphous phosphene images as a visual epiphenomenon

To study the spontaneous periodic synchronized bursts the researchers prepared cultures of dissociated cortical neurons and allowed them to mature for several days in vitro (DIV) After 3 to 4 DIV when concenshy

trations of extracellular magnesium were low electrodes began to detect spontaneous synchronized bursts of low frequency calcium transients (between 01 and 1 Hz) that originated in different locations on the sheet every 10 to 20 seconds and spread across the sheet of cells at a relatively slow speed averaging 50 mmsecond The researchers could not predict where a wave would originate or where it would expand rather the initiation and expansion of waves was generated by spatial and temporal summation of a continuous random background of synaptic inputs including miniature spontaneous synaptic events but the pattern was not random since waves propagated sequentially from electrode to electrode as each local group of neurons charges up its neighboring nontefractory areas rather than in a random sequence of regions38

The excitability of the cells in the sheet determines the probability first that there will be a synchronous burst and second that it will spread in a particshyular direction Cells become more excitable as the cultures mature which means the refractory intervals between successive bursts were much shorter in mature cultures (gt 30 DIV) than in early cultures laquo 7 DIV) Some cells became so insensitive to inhibition that they continued to fire bursts even when extracellular concentrations of magnesium were relatively high Finally there were refractory periods of 5 to 10 seconds during which no bursts occurred even when an electrical stimulus was applied This refractory interval for cultured networks is slightly longer than the refractory interval observed of the cortical slow wave in vivo which 25 to 4 seconds 18- 19

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 136

Based on the observations about cortical slow waves we can predict that phosphenes generated as epiphenomena of delta wave activity will present the following signal characteristics (1) signals that appear at unpredictable locations in the VF (2) signals that expand and diverge asymmetrically following unpredictable trajectories which may encompass large areas of the VF (3) signals that move relatively slowly (50 mmsec) (4) signals that recur with a period of 2 to 4 seconds reflecting entrainment by the cortical slow wave (5) signals that do not terminate automatically after a predictable number of cycles

The spatial patterns of phosphene mists and thalamic delta waves are similar The spatiotemporal characteristics of amorphous phosphenes match the pattern of wave propagation associated with periodic spontashy

neous synchronized bursts in large neuron networks the amorphous phosphenes enter the visual field at unpredictable locations expand and diverge asymmetrically with a slow steady rate of flow follow trajectories that are unpredictable and exhibit a refractory interval The amorphous mists do appear to have a periodicity although the author is unable to sustain the vision while also counting the seconds therefore he is unable to determine if it compares to the period of the cortical slow wave (25 to 4 seconds) but his impression is that it feels roughly the same as as with receding annuli which recur at 5 seconds Also the refractory interval feels as if it decreases as the induction session is extended These similarities suggest that the amorphous phosphenes are generated by stage 2 NREMS delta wave activity which is an activity governed by the reverberation of the cortical slow wave in thalamoshycorticothalamic circuits The cortical slow wave is referred to the LGN where it modulates the firing of visual relay cells in the laminae and since relay cells do not have local dendritic connections the expansion of a wave of depolarshyizations moving from one relay cell to the next across in the laminar surface will mirror at least in part the expansion of the cortical wave that is spreading contemporaneously through locally-connected cortical cells

PART III RETENTION OF CONSCIOUSNESS

In a normal transition to NREMS the volley of synchronous spindle bursts that marks the onset of stage 2 NREMS overwhelms the normal firing pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 137

of thalamocortical cells preventing their relay of afferent sensory signals and inducing a loss of consciousness21 But the loss of consciousness cannot be timed precisely using cortical EEG the thalamus is too remote for the onset of spindling to be reliably detected by scalp electrodes39 In experiments with cats where electrodes could be implanted in the thalamus researchers found that spindling often reached peak levels of activity in the thalamus-a level of activity consonant with stage 2 NREMS-at a time when the cortical EEG was still showing intermittent desynchronizations a pattern characteristic of the drowsy stage 1 transition not a fully-established stage 2 NREMS episode4o

In other words there is a short period of time in which the synchronous rhythms of stage 2 NREMS are installed in the thalamus but not in the cortex where cortical neurons continue to depolarize in response to afferent sensory signals

T his finding suggests a possible explanation for the authors ability to retain consciousness while spindle bursts are sweeping through the LGN if he is able to extend the duration of this time lag between

the onset of spindling in the thalamus and spindling in the cortex if he is able to stimulate the visual cortices in such a way that they continue to depolarize then he may be able to keep on processing visual signals-to remain visually aware-even after the non-visual thalamus and non-visual cortex become entrained by synchronous sleep rhythms The authors induction technique includes several behaviors which are known to enhance the responsiveness of visual neurons-eye movements attentive fixation and an attitude of expectancy

Effects of eye movements and attention on the LGN Sustained convergence causes periorbital proprioceptors to send excitatory feedback directly to the LGN41 Also convergence further enhances the excitability of geniculate cells by stimulating the superior collicus (SC) which sends its own excitatory signals to the LGN42-43 These signals from the SC are known to selectively enhance the excitability of visual relay cells that represent the periphery of vision44 We know in the authors case that the SC is being stimulated because he is able to keep on fixating an ability which would normally be lost during the transishytion to NREMS45 The ability to fixate can be retained however if the SC is stimulated (even if stimulated during NREMS)46

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 138

Effects of eye movement attention and expectancy on the primary visual cortex The PET study of mental imagery by Kosslyn et al 3 showed that even a baseline resting state of relaxed immobile expectancy can generate signifishycant increases in neuronal activity in the primary visual cortices Further increases can be induced by sustained eye movements

A sustained convergence will release a stream of ponto-geniculo-occipital (PGO) waves These PGO waves called eye movement potentials or EMPs last only as long as the eye movement1747 whereas the PGO waves associated with rapid-eye-movement sleep (REMS) fire continually for the duration of the REMS episode Both REMS-related PGO waves and EMPs have the same desynchronizing effect on the visual pathways they move through the LGN depolarizing the thalamocortical cells which relay the signals to cortical neurons The responsivity of neurons in the primary visual cortices is enhanced by the stimulation of PGO waves 1747-49 If the passage of EMPs causes the genicushylate relay cells and their cortical targets to depolarize regularly then a volley of 4 spindle bursts moving through the same pathways will register as just another series of depolarizations in effect the spindle bursts are processed by the visual system as if they were sensory signals sent from the retina rather than an event stimulated by endogenous mechanisms

T he impact of eye movements and ftxation on the parietal visual cortex Convergence and attentive fixation will also enhance the responsiveness of light-sensitive parietal visual neurons (PVNs) in area PG of the

posterior parietal cortex 50 In experiments where monkeys are trained to fix their attention on a screen-and to keep on fixating even if no targets appearshythe excitability of these light-sensitive PVNs increases by as much as 350 51

52-53Responsiveness is also facilitated by the angle of gaze Also area PG is the first region in the visual pathways containing individual neurons with the capacity to respond to large bilateral stimuli moving in opposite directions along the central meridians of vision (opponent vector motion) 853-55 Facilitation of PVNs in area PG has the effect of sensitizing the subject to bilateral opponent vector motion and this is especially true if the movement appears in the periphery of the VE 8

Intracortical ampliftcation and feedback to the LGN When PGO waves and signals from the SC arrive in the primary visual cortex they may be relatively weak however weak signals can be amplified by reverberating in large networks

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 139

of cortical cells linked by local projection 56 There are nine times as many excitatory links among cortical cells as there are projections from the visual cortex to the LGN an imbalance which suggests leads Suarez Koch and Douglas to propose that geniculate input provides only a minor fraction of the excitatory input the majority originating in neighboring and recurrently connected cortical cells57 If the excitabiliry of cortical neurons is slightly higher than normal then this process of amplification may continue even after the LGN signals that initiated the reverberation are no longer being transmitted by the LGN ( a hysteretic mode of operation) 57

Feedback from hyperexcited cortical neurons will stream back to the LGN via corticogeniculate projections which outnumber geniculocortical projections ten-to-one One effect of this feedback is that the LGN is

able to absorb large amounts of information flowing back from the cortex 58

As signals reverberate back and forth in thalamocorticothalamic circuits a matching process takes place those geniculate relay cells that fire in patterns consistent with the firing patterns of active cortical cells will have their responshysivity enhanced while those geniculate cells that fire in patterns not consistent with cortical cells will be suppressed 59

Preservation of consciousness by selective facilitation of the visual pathways By combining all of the facilitatory effects produced by the authors eye movements and attentive fixation-(l) stimulation of the LGN by feedback from periorbital proprioception both directly and indirectly via the SC (2) the release of PGO waves (EMPs) that facilitate neurons in the LGN and primary visual cortex as they pass (3) the facilitation of the primary visual cortex by a state of relaxed immobile expectancy (4) attentive fixation and angle of gaze that facilitate PVNs in area PG (5) intracortical amplification of signals received from the LGN and (6) corticogeniculate feedback that stimulates the LGN-we delineate a circuit of enhanced excitability that extends from the LGN through the post-geniculate visual heirarchy to area PG where signals are integrated into representations of objects

The hyperexcitability of neurons all along the post-geniculate visual pathways creates conditions in the visual cortices which are similar to those present during EEG-desynchronized states of waking and REMS Therefore neurons in the visual pathways are too excitable to be entrained by synchronous bursting

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 140

patterns when spindle waves move through them instead the spindle bursts stimulate visual neurons to depolarize and then recover as happens in response to afferent sensory signals during waking states It is important to note that for this to occur none of the constituent neuron assemblies is required to perform an abnormal operation the abnormality is a function of the authors intent to activate contemporaneously neuron assemblies that would not normally be co-activated

PART IV HYPNOTIC ANALGESIA

Manipulation of spatial attention as a method for alleviating pain sensations In a theoretical article on the neurophysiology of hypnosis Crawford and Gruzelier60 propose that variations in hypnotizability are function of variability in the efficiency of the frontolimbic (anterior) attentional system in humans high-hypnotizables are better able to sustain focused attention on a task and to ignore extraneous stimuli than are low-hypnotizables

I na related empirical study that compares the use of attention by subjects with high versus low hypnotizability Crawford Brown and Moon61 report that highly hypnotizable persons continue to show physiological reactivity

while cognitively not perceiving the painful stimuli Through disattentional processes they can dissociate themselves from the awareness of pain The authors phosphene induction behaviors-and the cutaneous analgesia he experishyences-appear to involve the same kind of behaviors that is a mobilization of frontolimbic attention used to withdraw attention from external stimuli and to concentrate it on internally-generated phosphene images This suggests the hypothesis that the mechanisms that generate phosphenes might also produce hypnotic analgesia There are several ways that visual signals and pain signals might interact to produce this analgesia

Competition between pain and vision signals for limbic registration The fully-developed sensation of pain requires integration of rwo kinds of informashytion Signals that encode the location and intensity of a noxious stimulus (nociceptive signals) are relayed via the thalamus to the somatosensory cortices which registers only the sensory-discriminative aspects of pain perception62 before reaching consciousness the nociceptive signals must be sent to the limbic

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 141

system where they are linked with signals from long-term memory that encode the affective significance the stimulus has acquired for that individual Studies of brain metabolism show this linking of somatosensory information with limbic associations takes place in the anterior cingulate (CG) and anterior insula62-64

PET studies also show that the anterior CG is activated when subjects shift their spatial attention in response to expectations as to where

66stimuli will next appear65- This is precisely what takes place during the state of immobile expectancy that induces phosphenes Since visual signals and nociceptive signals both require limbic enhancement which is only possible if they get access to the anterior CG there might be conditions in which the two types of afferent sensory signals have to compete for that access In a theoretical article on the mechanisms of attention Posner and Rothbart67

propose that visual signals can interfere with nociceptive signals by blocking access to the anterior CG As behavioral evidence they cite studies showing that when young infants make distress calls they can be distracted by the presentation of a new visual stimulus We have shown the evidence of such control at about three months Orienting to visual events can be employed to quiet or calm negative vocalizations However the distress appears to be maintained and reappears when the infants attention to the stimulus is reduced Caregivers also report the use or visual orienting to block overt manifestations of distress at about this age 67

The effects of disattention on the somatosensory cortices If there is a competition between visual signals and nociceptive signals for access to the anterior CG it is likely that the competition will be affected by the relative volume of signals received A recent study suggests that focusing attention on internally-generated visual stimuli may reduce the number of nociceptive signals relayed by the somatosensory cortices Drevets Burton Videen Snyder Simpson and Raichle68 have shown that the mere anticipation of a touch at a specific cutaneous site increases the flow of blood to those cortical somatosenshysory neurons that are linked with that site where touch is expected and decreases the flow of blood to neurons linked with sites where touch is not expected In this experiment the researchers designated touch as the behaviorally significant sensory stimulus but their findings suggest that the outcome could be reversed if the instructions were reversed if subjects were

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page J42

instructed to direct attention away from a cutaneous site where a noxious stimulus was being applied if they were instructed to relax close their eyes and concentrate on the play of phosphenes in the visual field as the behaviorally significant sensory stimulus then it would be reasonable to expect that the flow of blood would decrease to the somatosensory neurons linked with the cutaneous stimulus and that the flow of blood would increase to the visual cortices The decrease in blood flow to somatosensory neurons implies less neuronal activity which implies that fewer signals are being sent forward to the anterior CG than would have been sent if instead the subject were treating the touch as the behaviorally significant sensory stimulus If fewer pain signals arrive at the anterior it is reasonable to infer that the conscious experience of pain will be muted by the diversion of attention to internal visual stimuli

Differential impact of sleep rhythms in the visual and nonvisual thalamus There is another mechanism that might also contribute to the analgesic effect of inducing sleep rhythms PET studies show that

the thalamus is involved in the relay of nociceptive signals to the cortex63 although some confusion remains about which kinds of signals are relayed by which subregions in the thalamus62 One thalamic site clearly identified by anatomical studies as a relay for nociceptive signals is the ventroposterior lateral nucleus (VPL)69 If synchronous sleep rhythms are active in the thalamus we can reasonably expect that the VPL will itself be entrained by synchronous oscillations and that it will relay the sleep rhythms to somatosensory cortices Relay neurons in the VPL are not stimulated by feedback from eye movements and fixation as are relay neurons in the LGN which suggests that sleep rhythms may impede the relay of nociceptive signals via the VPL but not the relay of visual signals via the LGN

Brain waves associated with anesthesia and NREMS The hypothesis presented here-that consciousness can be preserved despite the presence of NREMS activity-is consistent with a recent report that the kinds of fast brain waves which are normally associated with conscious states are also present during NREMS and anesthesia two states which were thought to involve minimal brain activityJo Another recent study found that there is a close resemblance between the slow brain waves that appear during NREMS and those that appear during certain types of anesthesia71

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 143

bull bull bull

CONCLUSION

In this paper we have presented evidence supporting the hypothesis that phosphene images can be generated as an epiphenomena of thalamic spindle bursts and delta wave activity normally associated with NREMS The prereqshyuisites for inducing these sleep rhythm phosphenes are relaxed immobile expectancy sustained convergence and attentive fixation of an undifferentiated visual field Our hypothesis provides a necessary and sufficient explanation for the authors induction of phosphenes and perhaps also for the generation of phosphenes reported to appear spontaneously during the drowsy transition to sleep (hypnagogic states) during sensory deprivation or during certain kinds of prayer or meditation all of which involve a similar state of relaxed immobile expectancyJ2

CORRESPONDENCE Philip T Nicholson bull 52 Norfolk Road bull Chestnut Hill MA 02167

REFERENCES amp NOTES

1 M 1 Posner Modulation by Instruction Nature 373 (1995) pp 198-199 2 J Reissenweber E David amp M pfotenhauer Investigations of Psychological Aspects of

the Perception of Magnetophosphenes and Electrophosphenes Biomedizinische Tecknik 373 (1992) pp 42-45

3 S M Kosslyn W L Thompson 1 J Kim amp N M Alpert Topographical Representations of Mental Images in Primary Visual Cortex Nature 378 (I995) pp 496-498

4 P E Roland amp B Gulyas Visual Memory Visual Imagery and Visual Recognition of Large Field Patterns by the Human Brain Functional Anatomy by Positron Emission Tomography Cerebral Cortex 51 (1995) pp 79-93

5 H Benson The Relaxation Response (Morrow New York NY 1975) 6 ] H Schultz amp W Luthe Autogenic Training a Physiological Approach to Psychotherapy

(Grune amp Stratton New York NY 1969) 7 E Jacobson Progressive Relaxation (University of Chicago Press Chicago IL 1938) 8 M A Steinmetz BC Motter C] DuffY amp V B Mountcastle Functional Properties

of Parietal Visual Neurons Radial Organization of Directionalities Within the Visual Field Journal ofNeuroscience 71 (1987) pp 177-191

9 R R Edelman Magnetic Resonance Imaging of the Nervous System Discussions in Neuroscience 71 Elsevier Science Amsterdam (I990) also J H Newhouse amp ] I Wiener Understanding MRI 1st Ed (Little Brown Boston MA 1991)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 144

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

INTRODUCTION

To understand the mechanisms involved in the exercise of voluntary control over mental processes it is important to learn more about how different kinds of attention affect local brain networks I This paper

describes how the authors manipulations of spatial attention during a relaxed immobile expectant state induce light sensations in the absence of an external light source (phosphenes) The endogenous mechanisms that produce this effect can be identified ad hoc by analyzing the spatiotemporal characteristics of these phosphenes

A recent study suggests that an unexpectedly large number of people will selfshyinduce phosphenes during relaxed immobile expectancy 2 After telling 28 subjects they would be exposed to an extremely-low-frequency electromagnetic field the researchers only simulated their usual protocol without actually activating any electromagnetism Despite the absence of an external stimulus 90 of their subjects reported seeing phosphenes mostly colored moving phosphenes (73) The researchers concluded that phosphene reports associshyated with exposures to electrical or electromagnetic fields did not warrant further investigation on the grounds that the psychological component of the perception of electric and magnetic phosphenes must not be underestimated However their finding raises another question one the researchers themselves do not ask but which will be the focus of our investigation Why do so many subjects report seeing phosphenes while waiting in a state of immobile expectancy If these subjects did in fact see phosphenes what endogenous mechanisms might account for this phenomenon

In a recent positron emission tomography (PET) study of mental visualization subjects were asked to rest in a state of relaxed immobile expectancy while the researchers took measurements of brain metabolism for a baseline resting condition3 They assumed this state would generate only minimal levels of neuronal activity in the visual cortex and thus would serve as a good base for comparison with brain metabolism during the performance of assigned tasks The instructions (adopted from an earlier PET study4) were as follows subjects were asked to remain (1) supine (2) motionless (3) blindfolded with their eyes closed (4) not to say anything to tense their muscles or to change respiratory rhythms after inhalation of the tracer and (4) to have it

Subtle Energies amp Energy Medicine bull Volume 7 bull Numher 2 bull Page 112

black in front of their minds eye (ie not to have any visual imagery)3-4 A cortical EEG confirmed that all subjects had predominant alpha-rhythm as is expected when subjects are relaxed with eyes closed When they analyzed the results the Kosslyn team was surprised to find that the baseline resting condition generated a significant increase in neuronal activiry in the primary visual cortex an increase that antedated the performance of the assigned visual tasks The similarities berween the behaviors used as the baseline resting condition in the PET studies and the behaviors used by the author to induce phosphenes suggests that similar mechanisms may be involved In this paper we hope to identifY those mechanisms

METHODS

The author a fifty-year-old medical writer with no history of drug or alcohol abuse uses autohypnosis to disperse pain during dental or medical procedures to relieve muscle tension headaches to warm his extremities

and to induce sleep His method of autohypnotic induction resembles the generic relaxation response popularized by Benson but involves a more active manipushylation of eye position and attention 5 To begin inducing phosphenes the author lies on his back closes his eyes takes slow deep rhythmic breaths and gives himself silent instructions used in autogenic training such as let yourself relax or concentrate on the breathing6 If body or mind resists relaxing he tries progressive relaxation techniques which involve tensing and relaxing the large muscles of the body in systematic sequence

Once noticeable relaxation is present the author begins to manipulate eye position to accelerate dissociation He converges his eyes with enough force to elicit a continuing sensation of fullness or pressure in the eyeball At the same time he tests which of rwo different eye positions produces the strongest feeling of having the attention hone in or lock in on the fixation point at the center of vision (1) with eyes converged and slightly depressed as if focusing on the tip of the nose or (2) with eyes converged and elevated as if focusing on the forehead or crown If the eyes were opened in either of these positions they would produce a non-fused image of the external world (With long practice the response is conditioned so that a less forceful convershygence is needed to produce the same effect)

Subtle Energies 6- Energy Medicine bull VoLume 7 bull Number 2 bull Page 113

I n addition to manipulating eye position the author focuses all his attention on the fixation point at the center of the visual field even though at this early stage in the phosphene induction process the visual field remains

empty of everything except random metabolic discharge referred from the retina-the eigengrau or self-generated gray light When the attention is fixated strongly enough the author experiences auditory feedback-a distincshytive tinnitis cerebri that seems part sound but also part vibration This sensation originates inside the lower rim of the skull at about the level of the ears and feels as if it radiates upward on both sides It sounds like bird wings fluttering the sputtering of an open wood fire or a dull buzz The reader can experiment with eliciting a version of this same tinnitis by staring intently at some external object located just beyond the reach of an extended arm With practice this tinnitis can be sustained for long intervals and used as a feedback signal to mark the efficiency of dissociation Long practice also conditions this response so that a slight convergence of the eyes a straight-forward stare and fixed attention are sufficient to evoke the tinnitis and then the phosphenes The author continues the stereotyped eye movements and attentive fixation until phosphenes appear and for the duration of the phosphene displays

No less important than sustained convergence and attentive fixation is the ability to keep the level of arousal low and the mental field free of distractions The author remains passive and ready to acquiesce in whatever happens To minimize the distraction of unwanted thoughts images emotions itches or pains he uses a traditional meditation strategy-not attempting to resist distracting content but rather treating its arrival with indifference letting it drift freely in and out of consciousness This disengagement from potentially disruptive thoughts combined with steady breathing and the intense focusing of attention preserves equanimity and maintains a low level of arousal

Pain control requires adding another strategy In response to a painful stimulus the large muscles of the body usually tense involuntarily and fear of further pain breaks into awareness The author counters these instinctive and involunshytary reactions by deliberately posing the thought that the pain is not actually attached to the body that the pain can be given away by allowing it to flow out of the body and to disperse in all directions in which case the author need not take action in order to escape or avoid the pain This mental strategyshyin effect a deliberate abandonment of the normal vigilance which is oriented

Subtle Energies amp EnerfJ Medicine bull Volume 7 bull Number 2 bull Page 114

toward behaviorally significant external stimuli-results in a sudden preCIpIshytous drop in tension and restoration of the former relaxed state This reshyrelaxation occurs immediately after the muscles tense involuntary in response to the painful stimuli Keeping relaxed helps diffuse the pain sensations and the anxiety about pain The anticipation that relaxation (and the relief it brings) can be quickly restored after the next painful stimulation creates confidence that events are not out of control and that therefore it is not necessary to divert ones attention from the focus on the visual field that generates the phosphenes

The authors phosphene induction method closely resembles the behaviors used as the baseline resting condition in the PET studies except that in those studies subjects were not explicitly instructed to converge their eyes or to fixate their attention However the authors attempt to carry out their instructions-lying motionless with eyes closed and having it black in front of the minds eye results in his eyes focusing automatically on the near visual field an operation which requires some convergence (although not as much as the author would normally use) His attention also focuses automatically on the center of the empty visual field If the authors experience is typical then the two sets of behaviors may be virtually the same with differences being in degree not in kind

OBSERVATIONS

PHOSPHENE RECEDING ANNULI

The threshold sequence of phosphene images is illustrated in Figure 1 Just before the appearance of phosphene there is a fleeting sensation of a movement inward from 3600 of the peripheral visual field (VF)

as if a dark annular wave were moving through the dark background with so little contrast that it is almost imperceptible This annular wave suddenly illuminates while still in the far periphery of the VF (at about 80 - 60deg of isoeccentricity) presenting a bright thin phosphene annulus yellow-green in color that decreases in diameter at a constant rate preserving its annular symmetry until it disappears into the centerpoint after 4 seconds of elapsed time (estimated by counting 1001 1002 etc) There is an interval

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 115

0- 05 sec 10 sec 15 sec

20 sec 25 sec 30 sec

Figure 1 Schematic drawings ofreceding annuli phosphenes At first there is a sensation of movement inward from 360 0 in the periphery of vision then a bright thin yellowshygreen phosphene annulus sudden~y illuminates at about 80 60 of isoeccentricity The edges ofthe annulus are well-defined but more diJfose than this computer drawing program can depict-like a wellformed smoke ring The annulus preserves its symmetry as it shrinks steadio in diameter at a constant rafe offlow creating the illusion that it is receding toward the center of vision At 2 seconds the empty space inside the annulus fills abrupto with a disk ofbrighter phosphene At 4 seconds the image disappears into the centerpoint At 5 seconds another annulus sweeps into the periphery The author sees a total of4 receding annuli

of 1 second then the next wave appears at the periphery of the VE Midway in the trajectory-at 2 seconds-the empty interior of the annulus fills abruptly with a disk of slightly brighter phosphene A sequence of annuli usually terminates after 4 images although the number of annuli can be increased by diverting the attention for a moment and then refocusing

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 116

While the color of the annulus has remained the same over time the color of the filling-in disk changed after about two years of intermittent phosphene induction from yellow-green to blue The change began with tiny flecks of blue flashing amid the green just as the disk disappeared Over a period of several weeks the amount of blue expanded and appeared earlier in the fillshysequence Within a month the entire fill-disk was blue

The shrinking annuli create a psychological illusion of a ring of light receding toward a distant point in 3-dimensional space and pulling the attention into a vortex or paradoxically the same progression can create a sensation of falling backwards an illusory motion that resembles an effect produced by optic flow Motion in the visual periphery elicits in the stationary observer an illusion of self-motion (vection) indistinguishable from real motion The illusion of vection is compelling for it dominates contradictory proprioceptive signals For example subjects presented with optic flow consistent with backward self-motion perceive backward motion even if they ate actually walking forward 8

T he same receding annuli appear spontaneously as hypnagogic images while the author is reclining and waiting for sleep The receding annuli appear whenever the authors mind and body are relaxed his eyes closed

and his attention focused straight ahead-essentially the same behaviors used for self-hypnosis-but in the hypnagogic context virtually no effort is required the receding annuli feel as if they were released spontaneously not induced If the author is not relaxed or if he is distracted by a headache or importuning thoughts then the luminous receding annuli do not appear Instead the author loses consciousness abruptly at the onset of NREMS

AMORPHOUS EXPANDING PHOSPHENES

(A) loCAL RANDOMLY-DISPERSED EXPANDING WAVES Figure 2(A) illustrates one kind of amorphous phosphene mist that appears after the receding annuli sequence terminates These phosphenes are small amorphous swirls of yellowshygreen that coalesce suddenly at unpredictable locations in the VF and expand for a second or two then fade into the background There are often several images drifting in the visual field at the same time each in a different stage of evolution and the density of the phosphene seems to vary with some areas appearing thin and translucent others more opaque-like puffs of smoke that

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 117

10 seconds 15 sec 20 sec

25 Bee 30 sec 35 sec

expand and curl aimlessly then dissipate Because these waves are so unpredictable and formless the author is unable to predict the mean number of signals per episode the period between signals the site of entry or exit or to define a typical trajectory other than in the abstract generic manner used above The signal-to-noise ratio in these phosphenes is very low since phosphene stands out against the background there clearly is a signal but this signal presents so little pattern that it is essentially a form of phosphene noise These localized pulsations may continue for several minutes but usually within a minute or two they are superceded by the type of amorphous wave described next

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 118

Figure 2 [focing page Schematic drawings of of amorphous expanding phosphenes (A) Brief randomly-dispersed localized pulses These phosphenes are the first to appear after the receding annuli They coalesce at unpredictable locations in the IF expand asymmetrically for a second or two then dissipate into eigengrau before there is time to extend very for beyond their locus of origin (B) Periodic unidirectional amorphous expanding waves These phosphene waves enter the periphery ofvision from one hemifield presenting as a loosely-defined crescent (hemi-annular) cloud that mirrors the curvature of the peripheral rim The leading edge of the wave expands and flows across the vertical meridian into the opposite hemified swirling around the periphery curling inward and merging while at the same time the trailing edge ofphosphene dissipates rapidly in those regions over which the wave has already passed like mist or smoke evaporating in air The author is unable to time these waves but their duration fiels roughly the same as for receding annuli ie about 4 seconds Waves appear one after another in a cluster with a refractory period between clusters during which no waves appear After a prolonged session ofself-hypnosis the phosphene may not completely dissipate between successive waves in which case the residual phosphene accumulates in a vaguely-circular cloud shape with a small area its center that undergoes continual perturbation the phosphene pulls back leaving a small Mrk circle at the center of the cloud then fills back in then pulls away again ebbing and flowing in like manner until the cloud dissipates At this stage the image resembles an eye with a phosphene iris and a dark inner pupil (C) Twoshytone phosphene During a prolonged session the phosphene at the very center of the amorphous cloud becomes much brighter more fine-grained almost opaque with highly saturated color When a hole (pupil) appears in the center ofthe cloud forming an eyeshyimage the brighter phosphene becomes a thin bright rim lining the Mrk hole from this bright inner rim tiny promontories ofbright phosphene flare out into the Mrk hole twist and coil and collide with other flares forming webs and momentarily filling-in the Mrk hole or receding back into the rim The two-toned phosphene does not only appear in conjunction with the eye-shape clouds it also manifests at the center ofa variety ofelusive ever-changing shapes It is always restricted to the area offoveal vision

(B) PERIODIC UNIDIRECTIONAL AMORPHOUS WAVES These phosphene waves sweep in from one hemifield as shown in Figure 2(B) Often the wave has a vaguely crescent shape at the outset that conforms to the concave curvature of the peripheral VF then the crescent shape gives way as the wave expands rapidly in divergent directions flowing smoothly across the vertical meridian to envelop those regions of the VF that have not yet been illuminated As the leading edge of the wave expands the rear edges are already beginning to dissipate The swirling movement and the contraction of outer boundaries leaves a cloud of phosphene near the center of the VE This cloud may dissipate rapidly or it may persist for several seconds during which a pertur-

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 119

bation takes place at the center of the cloud the phosphene ebbs away from this region leaving a tiny dark hole then the phosphene fills back in then it ebbs and fills again-a fluctuation that continues as long as the phosphene cloud is visible During the perturbations the phosphene vaguely resembles the iris of a human eye with an interior dark space as its pupil This eyeshyimage is seldom symmetrical and its boundaries are always changing

(c) TWO-TONE PHOSPHENE When the phosphenes are induced over a prolonged period of time the phosphene in the central region representing foveal vision presents a more intensely bright more opaque (finely-grained) character than the rest of the cloud as shown in Figure 2(C) When this brilliant opaque phosphene appears as part of an eye-image it forms a thin rim surrounding the pupiL From this rim flares jut out into the dark pupil space coil about merge or recede back into the rim

The periodic unidirectional amorphous waves do not terminate after a stereoshytyped sequence they can be evoked over prolonged rime periods if the autohypshynotic behaviors are maintained The author is unable to retain the vision of these amorphous waves while simultaneously counting the number of seconds elapsed it is his impression however that the duration of amorphous expanding waves feels about the same as for receding annuli that is a duration of about 4 seconds per wave The amorphous waves usually appear in clusters followed by a refractory interval during which no phosphenes appear even if induction behaviors are sustained

PHOSPHENES SUPERIMPOSED ON ExTERNAL OBJECTS

The author can observe amorphous phosphene images with his eyes open if he is in a room dark enough that colors cannot be distinguished or if he is

in a lighted room but one where he can keep his eyes diffusely focused on a relatively undifferentiated surface such as a wall or ceiling with a light and uniform color and no distracting decorative adornments In open-eye viewings phosphenes appear as faint translucent waves of yellow-green mist

superimposed over the surface or in the dark space that fills the darkened room If the author attempts to focus on the features of external objects the phosphenes disappear

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 120

RECEDING ANNuLI EVOKED BY MAGNETIC REsONANCE IMAGING (MRI)

A s a patient undergoing an MRI scan the author observed an unusual sequence of receding annuli He was not relaxed as in a normal induction but rather anxious about his medical condition and about

being confined in the narrow MRI tube To keep calm he concentrated on breathing slowly and stared straight ahead While the sound of MRI machine was audible the author observed a stream of receding annuli that differed from the usual sequence (self-induced and hypnagogic) in three ways (I) the MRI annuli did not terminate at 4 cycles but continued for as long as the author kept his attention focused (2) the MRI annuli were only yellowshygreen in color even though in other inductions the fill-in disk had already changed from green to blue and (3) MRI annuli completed their trajectoshyries in half the normal time disappearing in 2 seconds instead of 4 An interval of 2 seconds between radio pulses is often selected as optimal interval for capture of the signals emitted by hyperexcited atoms in the subjects body

10during the precessional relaxation 9- These observations suggest that energy released in the wake of the radio bombardment during MRI moves through the LGN as a standing wave in the same way that spindle bursts move but that the 2-second duration of the MRI wave is not long enough to activate the neurons that generate a blue sensation

THE ANESTHETIC EFFECT ASSOCIATED WITH SELF-INDUCED

PHOSPHENES

On several occasions the author has preferred to undergo minor surgery without local anesthetic and to rely instead on autohypnotic analgesia-for example during extraction of an infected abscess from the back during laser surgery to

remove keloids and during the filllng of dental caries His experience on a recent occasion when a dentist had to abrade the surface of six teeth with damaged enamel in order to create a strong bonding surface are worth describing here because the experience implies that spindle waves can be induced even during a state of high physiological arousal For this appointshyment the author arrived in the office too late to hypnotize himself in advance

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 121

so he had to begin the normal induction procedures after the dental work was already underway

A s the dentist worked on the first tooth the author experienced apprehension sharp sensations of pain and an involuntary tensing of the large muscles of the body with each application of the drill As

the author kept his eyes converged and his attention focused on the center of the visual field the involuntary tensing in response to pain alternated with a precipitous relaxing of those same muscles immediately after the stimulus With the repeated relaxation came a sense of relief and of letting go that amelioshyrated the pain The pain-driven relaxation was much stronger than the relaxation that normally accompanies the authors self-induction of phosphenes and the alternation of a pain-driven tensing on one hand and the distancing effect of focusing attention on the visual field on the other hand resulted in a rapid dissociation from all external and internal stimuli including a signifishycant amelioration of painful sensations

Most striking is the fact that by the time the dentist reached the third toothshyafter only a few minutes of this pain-driven self-hypnosis-the author saw a normal sequence of 4 receding annuli followed by swirling clouds of amorphous expanding phosphene even though the dentist was still using the drill contemporaneously This experience suggests that thalamic sleep rhythms can be voluntarily induced even when the subjects level of physiological arousal is high

SIMILARITIES WITH ATTENTION-INDUCED PHOSPHENES

REpORTED BY OTHER OBSERVERS

Taxonomies of phosphene images always include examples of simple geometric phosphenes with circular or semi-circular shapes (disks annuli or crescents) as

14well as formless phosphene mists 11 - There are also a number of anecdotal accounts that are relevant for example Friedman an opthamologist who studied entoptic images by introspection describes a similar sequence of annuli induced by sustained inward concentration Circular waves of blue color may be seen in the dark by the dark adapted retina They start at the

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 122

periphery and move inward toward the macula as a concentrically contracting solid circle disappear at the macula and begin again at the peripheryl)

A valuable but often-neglected resource of information about phosphene imagery is presented in the literature of religious mysticism Many mystics reported having seen translucent colored lights while absorbed in prayer or meditation A list of descriptions excerpted from self-reports is presented in Table 1 (These excerpts are representative of phosphene images that appear during states of calm and inward-oriented concentration they do not include images associated with paroxysmal raptures) These phosphene images exhibit a relatively limited set of shapes and colors the shapes are either circular (eg rings disks wheels suns) or formless (eg mists snow smoke) and the colors are usually a variant of either green or blue The phosphene visions of mystics display shapes and colors that are comparable to the images described by the author this and the many similarities in the behaviors used to induce phosphenes suggest that both sets of phosphenes have a common etiology

DISCUSSION

Whether the author uses self-hypnosis to induce phosphenes or experishyences them as hypnagogic images the threshold sequence of receding annuli has the same characteristics In both these

instances the antecedent behaviors involve a state of low physiological arousal combined with mental withdrawal from external stimuli These parallels suggest the hypothesis that phosphene displays are related to sleep-wake transitions

PART I RECEDING ANNULI AND THALAMIC SPINDLES

Mechanisms controlling the transition from waking to NREMS Based on the work of several research teams16-20 a consensus scenario for the generation of NREMS has emerged In this scenario NREMS is the product of three brain rhythms that interact with each other in thalamocorticothalamic circuits During the drowsy transition to sleep which in humans is called stage l NREMS the low voltage activity in the cortical electroencephalograph (EEG) still shows a pattern of intermittent desynchronization The polarization of

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 123

Table I Excerpts from self-reports of light visions by religious mystics

HEBREW MYSTICS the appearance of the wheels was like the gleaming of beryl and the four had the same form

their construction being something like a wheel within a wheel Ezekiel like a dome shining like crystal spread out about their heads And above the dome something

like a rhrone in appearance like sapphire Ezekiel a round Iodder like a full sphere rolling back and forth before him bright blue R Abulafia A glowing light clear brilliance A purple light that absorbs all lights R Moses de Leon

HINDU AND BUDDHIST MYSTICS a perfectly round beautiful deep-blue shape of a size appropriate to the center of a mandala as

if exquisitely painted of extreme c14rity Tsong Khapa a luminous revolving disc studded with lights a lotus flower in full bloom Gopi Krishna both my eyes became cemered When this happened a blue light arose in my eyes like

a candle flame without a wick and stood motionless in the ajna chakra S Muktananda

MUSLIM MYSTICS [like] chandelierssublime lights [like] stars moon or the sun Sharafuddin aI-Maneri its color is deep blue it seems to be an upsurge like water foom a spring Najmoddin Kobra visualize yourself as lying at the bottom of a well [looking up at the light of the opening] and

the well in lively downward movement Najmoddin Kobra the color green is the suprasensory uniting all the suprasensories Alaoddawleh Semnani the light rises in the Sky of the hean taking the form of light-gilling moons Najm Razi

CHRISTIAN MYSTICS his own state at prayer resembles a sapphire it is as clear and bright as the sky Evagrius descending like a bright cloud of mist like a sun round as a circle Simeon Neotheologos saw something in the air near him He did not understand the rype of thing but in some ways

it appeared to have the form of a serpent with many things that shone like eyes although they were not eyes Ignatius of Loyola

the soul puts on a green amilia [cape worn on shoulders beneath armor] John of the Cross [the almilla is like a helmet which] coverS all the senses of the head of the soul It has one

hole rhrough which the eyes may look upwards John of the Cross a round thing about rhe size of a rixdaier all bright and clear with light like a crystal H Hayen I saw a bright light and in this light the figure of a man the color of sapphireblazing with a

gentle glowing fire the three were in one light Hildegard von Bingen saw a b14zing fire incomprehensible inextinguishable with a flame in it the color of the sky

Hildegard von Bingen saw placed beneath her fuet the whole machine of the world as if it were a wheel She saw herself phced

above it her eyes of contemplation magnetized towards the incomprehensible Beatrice of Nazareth I saw the eyes I do not know if I was asleep or awake Angela of Foligno kind of sunlit winged being like a childs head beneath two little wings Abbess Thaisia laquobullbull round patterns small circles would expand and eventually dissipate only to be followed by other small

circles of light Philip St Romain an extraordinary circle of gold light pulsating against a deep violet background There were

always four or fille As soon as one would fode another would appear Philip St Romain

middotItalics added to mark words referring to (l) rings appearing in sets of four (2) amorphous shapes such as clouds or flames (3) circular or eye-like shapes (4) colors from the center of the visible spectrum (gold yellow yellow-green green bluish green) and (5) colors from the lower end of rhe visible spectrum (blue purple violet)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 124

cell membranes (Vm) has already begun to drop (hyperpolarize) in the thalamic reticular nucleus (RTN) a thin sheath of GABAnergic inhibitory neurons that acts as a pacemaker When the Vm of RTN cell membranes drops to approximately V m -60 millivolts (mV) RTN cells stop firing single spikes which are associated with waking states and instead begin firing highshyamplitude 7-14 Hertz (Hz) spike-bursts These bursts wax and wane over 1 to 3 seconds-hence the name spindle -and recur at 3 to 10 seconds Spindle volleys are relayed across the cortical mantle by thalamocortical (TC) sensory relay cells In human studies the primary criterion for onset of the first fullyshyestablished episode of NREMS or stage 2 sleep is the presence of globalized spindles in the cortical EEG

When spindle bursts from the RTN stimulate TC cells to fire in synchrony this synchronous bursting pattern overwhelms the normal capacity of TC cells to relay afferent sensory signals The loss of consciousness at the onset of stage 2 NREMS is thought to be caused by this blocking effect 21

While the RTN is firing spindle bursts through the thalamus another process is activated in the cortex large numbers of cells across the cortical mantle begin to oscillate at a very low frequency laquo 1 Hz)

The cortical slow rhythm referred back to the thalamus via corticothalamic circuits intensifies the hyperpolarizing effect of the RTN spindle bursts on TC cell membranes When V m -75 mV the TC cells begin to generate their own intrinsic calcium currents which further increases hyperpolarization At V m -90 mV the RTN neurons stop firing spindle bursts The TC cells continue to fire low-threshold calcium spikes in patterns which are controlled by the cortical slow rhythm The interaction of these two oscillations generates the delta waves (1 to 4 Hz) which are associated with stage 2 NREMS

In a study of sleep rhythms using the cortical EEG Uchida Atsumi and Kojima found that the mean number of spindles required to induce delta wave activity (that is to induce Vm = -90 mY) is 478 plusmn 162 spindles (from 3 to 7 spindles)22 The mean number of spindles in a volley remains the same for a single individual over multiple trials

Based on the consensus scenario for generation of NREMS we can predict that a phosphene image generated as an epiphenomenon of a thalamic spindle

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 125

Table II Dara show rhe degree of correspondance berween rhe pulse panerns of rhalamic spindles based on intracellular research and rhe sparioremporal panerns of receding annuli phosphenes induced by rhe author using a rechnique of self-hypnosis

Receding annuli phosphenes Thalamic spindle bursrs

Mean number of signals 4 annuli 487 (plusmn 16) bursrs

Sparial exrension vs Thin band 1 - 3 seconds durarion of signal ( 05 -15 cm)

Periodicity of signals 5 seconds 3 - 10 seconds

Simultaneity in LGNs Yes Yes

Point of entry Peripheral VF Ventral amp lareral LGN

Trajecrory Bilareral concentric Unknown

Rare of flow Cons rant rare Unknown

Signal-ro-noise rario High High (shorr bursrs) (sharp brighr discrere)

Termination of sequence Mrer 4 signals Mrer 487 (plusmn 16) signals

will present the following characteristics (1) a high-definition burst-like signal (2) that recurs within 3 to 10 seconds (3) that follows a trajectory compatible with having entered the LGN from the RTN (4) that has a predictable mean for the individual subject and a range that falls somewhere between 2 to 7 annuli and (5) that the spindles will terminate automatically

The temporal patterns of receding annuli and thalamic spindle bursts are similar Table II illustrates the close match between the timing of receding annuli phosphenes and thalamic spindle bursts The most striking similarities are the mean number of signals required to induce termination (4 annuli versus 487 spindles) and the interval between signals (5 seconds for annuli versus 3shyto-lO seconds for spindle bursts) Neither alpha theta nor beta waves present this kind of stereotyped temporal pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 126

T he spatial features of receding annuli are functions of geniculate anatomy A spindle burst moving through the LGN to the cortex will acquire certain distinctive spatiotemporal characteristics because of the

unique curvilinear and laminar anatomy of the LGN A drawing of a macaque LGN based on a clay model constructed by Le Gros Clark23 is shown in Figure 3 The primate LGN is composed of six sheets of cells or laminae that fold over a central hylus In macaques the hylus rises steeply as it extends rostrocausally forming a high arch at the posterior pole in humans the hylus is much more shallow but the functional anatomy is thought to be essentially

23 24the same in both cases - The geometry of the arch forces each lamina to bend so as to constitute in effect one-half of a conical surface and each lamina with its hemi-conical shape contains visual relay cells representing the contralatshyeral half of the visual field (VF) Operating as a pair the complementary hemishycones of the right and left LGN form the functional equivalent of a single conical surface which represents the entire VE This conical geometry of the paired LGNs means a burst of otherwise formless excitation will acquire a distinctive shape as it propagates through the laminae of the LGN Imagine a horizontal section moving along the surface of a cone from base to apex that moving section forms an annulus that shrinks in diameter as it approaches the apex but retains its annular symmetry throughout its trajectory

Figure 3 also includes drawings that show how Connolly and Van Essen24

converted the 3-dimensional structure of lamina 6 the largest and most dorsal layer into a 2-dimensional map Connolly and Van Essen used data obtained by Malpelli and Baker25 to superimpose a grid that specifies the areas in lamina 6 that contain TC cells representing various degrees of isoeccentricity in the VE We will use this map at a later point to show how the movement of a spindle wave through a pair of LGNs correlates with what appears in the VE

The location of the RTN relative to the LGN is also shown in Figure 3 The RTN spindle pacemaker is a thin sheath of GABAnergic inhibitory cells that extends along the surface of the whole posterior ventral thalamus not just the LGN This extension brings the RTN into close proximity with the portion of the LGN (lateral wing) that protrudes out from the main body of the thalamus Some of RTN wraps around and beneath the ventral edges of the LGN26 The RTN comes closest to the LGN in two areas along the ventral edges of the longest laminae (lamina 6 and 1) and along the edge of the lateral

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 127

DORSAL POLE DORSALPOIEA B

L1 L4 L3 L

DORSAL POlE DORSAL POIE (FOVEA)

G LATERAL WING

25

DORSAL POL (FOVEA)

10 _DIAL

20 WING

~

wing These areas contain TC cells that represent the far periphery of the VE If a spindle burst enters the LGN at locations where laminae are in closest proximity to the RTN-along the ventral edges-then the discharge of TC cells will begin in the most ventral portions of the laminae the regions that represent the far periphery of the VE This matches the phosphene sequence observed by the author

Our hypothesis about how this proximity between RTN and LGN affects the trajectory of spindle waves is illustrated in Figure 4 We propose that it is not possible for the author to observe a thin annulus of phosphene sweeping in from all 3600 of the peripheral VF unless spindle bursts exhibit the following

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 128

Figure 3 [facing page Drawings of primate geniculate anatomy and functional anatomy relevant to the generation ofphosphenes (A) Anterior view ofa macaque monkey LGN based on a clay model reconstruction by Le Gros Clark 23 (B) Posterior view ofthe same model showing 6 laminae folded over a central hylus to form lateral and medial wings with the hylus arching steeply upward near the posterior pole to shape the laminae into layers of hollow half-cones nested together Note that the lateral wing of the LGN is slightly larger than the medial wing so that in situ the lateral wing protrudes out from the main body of the thalamus creating a small knob visible during dissection 26 (C) Schematic drawing of an oblique section through median axis (also adapted from Le Gros Clark13 showing how the laminae fuse together at the anterior pole The afferent ganglion cell axons that form the optic tract (OT) penetrate through the anterior surface to reach their target relay cells in the laminae (D) Drawing of the most dorsal lamina-layer 6--separated from the rest of the LGN The geometric shape is a hollow half-cone so that right and left LGNs placed back-to-back form in effect a single cone Note also the position ofthe RTN shown here as a striped bar relative to lamina 6 The position of the striped bar shows that the RTN makes direct contact with lamina 6 at the edge ofthe lateral wing and also along the ventral edges (E - F) Schematic drawings adapted from Connolly and Van Essen24 that show how a 3-dimensional lamina-lamina 6--can be transformed into a 2-dimensional triangular figure lamina 6 is removed and its wings unfolded (E) creating a slightly asymmetric triangular figure (F) which is adjusted to an oblong shape (G) in order to superimshypose a grid matrix with minimal distortion The grid plots locations of TC cells that represent various isoelevations and isoazimuths in the VF locations derived from the experimental observations published by Malpeli and Baker 25 Note the relatively large amounts of laminar surface allocated to central vision (0 0

- 30 0) as compared

to peripheral vision (30 0 - 80 0)

characteristics (1) Spindle bursts must move simultaneously through both geniculate nuclei This pattern of movement is consistent with anatomical studies in primates that found axonal projections linking the right and left RTNs27-28 and with experimental studies in cats that found spindles appearing simultaneously in both right and left thalami 29 (2) Spindle waves must enter the ventral edges of the LGN first and move ventrodorsally in a highly coherent pattern-moving in effect as a standing wave This pattern of movement is consistent with in vitro experiments using sagittal slices from a ferret LGN where spindle waves originated spontaneously at the edge of a slice in an area which contains cells that represent peripheral vision then propagated toward that area of the slice containing cells that represent central vision in the ferret 3o

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 129

VF

PG BIlateral receptive lleJd of PVN YI(j Inward dmKooflality Adapled

0-- from Mortgr at at (1987)

V1

ibull t bull

RTN t t t t t t 1middot3 SECOlO BURSTS OF 7middot14 HZ SPiKES RECURRNG EVERY 3 10 SECONDS

To our knowledge the LGN is the only anatomical structure in the visual system that has the capacity of passively forcing a wave of excitation to flow across a conical surface thereby generating the sensation of a phosphene annulus that retains its symmetry as it shrinks in diameter The retina has a circular anatomy but it is not likely that the mechanical deformation of the retina would produce a wave that began simultaneously in all 3600 of the retinal rim nor that the symmetry of annular wave would be preserved as it flows inward toward the foveal region

The hypothesis presented here-that there is a structure in the visual system that imprints a conical shape on standing waves that move through it-explains

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 130

Figure 4 facing page Schematic drawing of contemporaneous events in selected regions of the visual processing hierarchy (A) The left and right RTNs fire spindle bursts simultaneously (B) The bursts pass through the right and left geniculate laminae as standing waves of depolarization entering from the ventral edges and moving ventrodorsally in parallel In order for the phosphene annulus to appear to be flowing at a constant rate the spindle wave flowing through the LCN must expand in width as it ascends ventrodorsally so that by the time the fill-in disk appears-when the center 30deg of the VF is covered by the phosphene annulus-the spindle wave must have expanded enough to activate relay cells in the most dorsal 50 of lamina 6 (C) Signals representing two complementary hemi-annuli are kept separate in the primary visual cortices (area VI) (D) Signals representing the two hemi-annuli are integrated into signals of a single annulus when they reach area PC in the posterior parietal cortex where the receptive fields of single parietal visual neurons have the capacity to register bilateral signals that exhibit opponent vector movement (that is signals converging from opposite directions along the central axes-as if an object were moving away from the viewer)46 Neurons in area PC also integrate wavelength (color) signals from the extrastriate visual pathway with signals about brightness motion and depth from the parietal visual pathway to compose a representation of an object in space-in this case of an annulus that appears to recede 32

the authors experience during MRI when he observed a continuous succession of receding annuli every 2 seconds in this view the energy of the electroshymagnetic bombardment when released during precessional relaxation flows through the geniculate laminae in the same way that the RTN spindle bursts do that is as a standing wave and thus the visual epiphenomenon is the same in both cases if the subject keeps the eyes focused straight ahead and the attention fixated In a study of phosphenes evoked by electricity in conjunction with hallucinogenic drugs Knoll Kugler Hofer and Lawder found that each subject sees specific kinds of phosphene at different frequencies and that these frequency-specific images are stable enough to be reproduced after six months31

They conclude that the tunability of the electrical stimulation frequenshycies within the EEG range to various definable phosphenes requires the existence of a resonance system One mechanism contributing to that resonance system may be the functional anatomy of the LGN

The colors of receding annuli as functions of geniculate laminar anatomy The colors of receding annuli phosphenes are consistent with the patterns of discharge spindle waves can be expected to stimulate as they move through

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 131

geniculate laminae As shown in Figure 5 the six laminae differ (1) in the types of wavelength signals relayed (2) in physical size and (3) in the area of the VF represented 24-25 Only 4 out of 6 laminae Cparvocellular layers 3shy6) contain TC cells that relay wavelength signals the other 2 laminae (magnocellular layers 1 and 2) do not encode wavelength Among parvocelshylular laminae only lamina 6 the longest and most dorsal layer contains TC cells that can represent the far periphery of the VF (from 800 to 50deg of isoeccenshytdeity) therefore when the spindle wave enters the peripheral VF only those wavelengths relayed by lamina 6 will participate in composing a cortical lightness record (See Zeki)32

I n lamina 6 ganglion cell axons arriving from the retina carry two kinds of wavelength signals (1) center-ON signals from medium-wavelength cones (M-cone center-ON) and long-wavelength cones (L-cone centershy

ON)33-35 Using the cone spectral sensitivity curves (adapted from Marks et al 36) we average the wavelengths that elicit maximal responses for M-cones (535 nanometers) and L-cones (520 nm) which yields a mean wavelength value of 550 nm In humans this wavelength generates a sensation of green or yellowshygreen the sensation observed by the author

As the spindle burst moves ventrodorsally it reaches the dorsal areas in the geniculate laminae which contain TC cells representing the central 0deg to 20deg of isoeccentrieity in the VE All 4 parvocellular laminae have TC cells which are potentially capable of representing this central region of vision but the authors observation that the color of the filling-in disk changed from green to blue implies that in the early years of phosphene induction the spindle wave must have remained close to the surface of the LGN stimulating only laminae 5 and 6 which generates a sensation of yellow-green When the fill-in disk was observed to change color from green to blue the spindle wave must have been rechanneled so that it began to penetrate below laminae 5 and 6 and to activate laminae 3 and 4 the only laminae that relay blue-sensitive signals (Sshycone center-ON signals)3 In light of the authors MRI experience it seems likely that a spindle wave requires a minimum of 2 seconds to reach the blueshysensitive cells of laminae 4 therefore during MRI when the receding annuli disappeared after 2 seconds half the normal duration the fill-disk had a green color even though it had long since change to blue in other induction settings with a 4-second trajectory

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 132

A REPRESENTATION OF THE VISUAL FIELD IN EACH LAMINA

orooqUtftc O-u OCIJ1SALfIOLI (I01flAj

0

10

20

30

40 n50 Of

60

70

20 loO 1Mgr_ II~ o UIpoundAS65 mn1MY-o actlvncL ~~~r

Jll-COMcetlImiddot~

II LAYERSU 3 GatQYancetl~ (1) ucon ceom-oyenF (2)l~cen()FF 3) ~ cenloH

II~ cng1loqctWIIIfNla

iICINe -- (t81Otdb1t1d~OH (2)~

80

B CONE SPECTRAL SENSITIVITY CURVES

S-COHS

WAVIlLllNG1llS OF UGHT IH NANOMllTERS (NM)

Figure 5 Phosphene color as a function of ganglion cell distribution in parvocellular laminae (Aj Schematic drawing ofthe proportion ofthe VF represented in each laminae The proportions shown here are based on the work of Connolly and Van Essen24 The

far periphery of vision (50 0 to 80 0 of isoeccentricity) is represented in only two laminae-laminae 1 and 6-and of these two only lamina 6 is a parvocelLular lamina capable ofencoding wavelength signals Therefore only those wavelengths relayed by lamina 6 will participate in forming a cortical lighmess record for the far periphery of the VP (B) Cone spectral sensitivity curves (adapted from Marks et al)36 Using these cone sensitivity curves we can estimate the sensation stimulated by a spindle wave moving through lamina 6 by averaging the wavelengths that elicit maximal responses for M-cones (535 nanomeshyters) and L-cones (520 nm) which yields a mean wavelength value of550 nm In humans this generates a sensation of green or yellow-green the sensation observed by the author when the receding annulus enters at the far periphery of the VP For a calculation of the cortical lightness record when a spindle wave moves through 20deg to 0deg ofthe VF stimulating all 4 parvocelfular laminae see the text and Figure 6

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 133

Once the spindle wave penetrates to laminae 3 and 4 it may activate all 4 parvocellular laminae stimulating TC cells to send contradictory wavelength signals for the same retinotopic location the signals sent from laminae 4 and 3 will encode blue light (S-cone center-ON plus M-cone center-OFF and Lshycone center-OFF) while the signals sent from laminae 5 and 6 encode yellowshygreen light (M-cone center-ON plus L-cone center-ON) This kind of contrashydiction does not occur in normal retina-based perception where light energy striking the retina is structured by the retinas center-surround and colorshyopponent organization to encode only one set of wavelength signals for each spatial locus 32 In Figure 6 we estimate the cortical lightness record that results when contradictory wavelength signals compete to be represented in consciousshyness Our calculations suggest that the outcome will be a mean wavelength which in humans elicits a dark blue or violet sensation

PART II AMORPHOUS PHOSPHENES amp THALAMIC DELTA ACTMTY

M echanisms controlling the transition from spindle bursts to delta activity In the consensus scenario for the generation of NREMS16-20 we noted that the RTN shifts to firing spindle bursts

when polarization of thalamic cell membranes drops to V m = - 60 mV At the same time cortical cells begin oscillating with a synchronous slow rhythm laquo 1 Hz) Both processes further decrease the Vm of TC cell membranes When Vm = - 75 mY TC cells begin to generate their own intrinsic calcium currents which also decreases V m At V m = - 90 mV RTN neurons stop firing spindle bursts At the same time the TC cells begin firing low-threshold calcium spikes in alternation with after-hyperpolarizations (LTS-AHP) Because sensory relay neurons in the LGN are not linked to one another by locally projecting axons the firing of one TC cell does not excite its neighbor However a lack of local connectivity does not mean that TC cells occupying the same laminae release their AHP-LTS calcium spikes in a random distribshyution rather spikes are released simultaneously by groups of cells in synchrony with the advent of the cortical slow wave In effect the distribution of LTSshyAHP spikes firing in the LGN is determined by the spatial propagation of the cortical slow wave Thus the delta wave (1 to 4 Hz) activity detected by cortical EEG during NREMS is a product of the interaction between the AHP-LTS calcium spikes released by TC cells and the cortical slow rhythm

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 134

CORTICAL PROCESSING OF CONTRADICTORY

WAVELENGTH SIGNALS

KEY _ Cells firing

cJ Cononol firing

Assume that as a spind6e wave moves through the LGNlt fires simultaneously aU the TC cells that represent a particular reUnoshytopic locus (x y) in each of the six laminae As a result cortical cells engaged In the higher level processing of visual signals will receive more wavelength signals representing retina locus (x y) than are generated by normal perception laquo and some of these afferent wavelength signals may contradict other signals arriving simultaneously

CORTICAL LIGHTNESS RECORD SlgnalSell

Intemal contradictions not congruent wilt pre

SmiddotON eristing neuron neta

s bullbull M-ON LmiddotON

3 bullbull M-OFF + L-OFF

a-ON 12

ROD-ON

No Internal eonlradlemiddot

--------1I =~8b~~~~~~~t signals

3+4

~ --OFF Excludes 6 Of 7 $J9n18

1+2 B-ON I

IWmiddotHmiddotI Signal Sell

1111111 No Intern1 conlrfldlcshy lion

Exelvdta 4 out of 7 efshy

bullbullbull bullbullbull ferant signals

No Intern1 contradic_ tionnee S-ON BshyOH and ROO-ON can all be coacllve at low lImlnance levels nef Ihe rod-eone break

ExchJde$ only 2 Ollt of 7 afferent signals

Figure 6 Selection of competing wavelength signals based on neuronal group selection This thought experiment is based on Edelman sconcept ofneuronal group selection 73 We assume that all possible combinations ofsignals will form sets and that all signal-sets will compete to make the most efficient match with pre-existing neuromd networks that have been forged over years ofnorma reti1U1-based perception We also assume that pre-existing neural networks are most likely to expedite those sets that satisfY 2 criteriI (J) the signals in a set do not contradict each other and (2) fower signals are excluded than in the other sets that satisfY the first criterion In our analysis Set 4 wins the competition because it does not contain internal contradictions and excludes fower signals (2 out of 7) than Set 3 excludes (4 out of7) It is not an internal contradiction that Set 4 contains both rods and cone Signtlls in normal retina-based perception when luminance levels approach the rod-cone break S-cone center-ON receptors send signas as do rod receptors and there is even evidence that rod activity may actually drive S-cone activity even after luminance levels foIl below the rod-cone break74 To calculate the cortical lightness record for Set 4 we average the wavelength that elicits maximal responses foom rods (511 nm) and for Sshycones (430 nm) which yields a mean wavelength of 470 nm which in humans results in a dark-blue or violet sensation

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 135

The cortical slow rhythm is an example of a generic pattern of neuronal excitashytion that occurs in large networks of neurons linked by local projections A recent experiment by Maeda Robinson and Kwana38 shows that networks of locally-connected neurons spontaneously generate periodic synchronized bursts of calcium transients that propagate across the network in an expanding spatial wave a pattern that represents a stable mode of firing towards which these neuronal networks relax following perturbations for example by electronic stimulation or by drugs Understanding the characteristics of these waves is an important prerequisite to understanding the mechanisms that produce the amorphous phosphene images as a visual epiphenomenon

To study the spontaneous periodic synchronized bursts the researchers prepared cultures of dissociated cortical neurons and allowed them to mature for several days in vitro (DIV) After 3 to 4 DIV when concenshy

trations of extracellular magnesium were low electrodes began to detect spontaneous synchronized bursts of low frequency calcium transients (between 01 and 1 Hz) that originated in different locations on the sheet every 10 to 20 seconds and spread across the sheet of cells at a relatively slow speed averaging 50 mmsecond The researchers could not predict where a wave would originate or where it would expand rather the initiation and expansion of waves was generated by spatial and temporal summation of a continuous random background of synaptic inputs including miniature spontaneous synaptic events but the pattern was not random since waves propagated sequentially from electrode to electrode as each local group of neurons charges up its neighboring nontefractory areas rather than in a random sequence of regions38

The excitability of the cells in the sheet determines the probability first that there will be a synchronous burst and second that it will spread in a particshyular direction Cells become more excitable as the cultures mature which means the refractory intervals between successive bursts were much shorter in mature cultures (gt 30 DIV) than in early cultures laquo 7 DIV) Some cells became so insensitive to inhibition that they continued to fire bursts even when extracellular concentrations of magnesium were relatively high Finally there were refractory periods of 5 to 10 seconds during which no bursts occurred even when an electrical stimulus was applied This refractory interval for cultured networks is slightly longer than the refractory interval observed of the cortical slow wave in vivo which 25 to 4 seconds 18- 19

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 136

Based on the observations about cortical slow waves we can predict that phosphenes generated as epiphenomena of delta wave activity will present the following signal characteristics (1) signals that appear at unpredictable locations in the VF (2) signals that expand and diverge asymmetrically following unpredictable trajectories which may encompass large areas of the VF (3) signals that move relatively slowly (50 mmsec) (4) signals that recur with a period of 2 to 4 seconds reflecting entrainment by the cortical slow wave (5) signals that do not terminate automatically after a predictable number of cycles

The spatial patterns of phosphene mists and thalamic delta waves are similar The spatiotemporal characteristics of amorphous phosphenes match the pattern of wave propagation associated with periodic spontashy

neous synchronized bursts in large neuron networks the amorphous phosphenes enter the visual field at unpredictable locations expand and diverge asymmetrically with a slow steady rate of flow follow trajectories that are unpredictable and exhibit a refractory interval The amorphous mists do appear to have a periodicity although the author is unable to sustain the vision while also counting the seconds therefore he is unable to determine if it compares to the period of the cortical slow wave (25 to 4 seconds) but his impression is that it feels roughly the same as as with receding annuli which recur at 5 seconds Also the refractory interval feels as if it decreases as the induction session is extended These similarities suggest that the amorphous phosphenes are generated by stage 2 NREMS delta wave activity which is an activity governed by the reverberation of the cortical slow wave in thalamoshycorticothalamic circuits The cortical slow wave is referred to the LGN where it modulates the firing of visual relay cells in the laminae and since relay cells do not have local dendritic connections the expansion of a wave of depolarshyizations moving from one relay cell to the next across in the laminar surface will mirror at least in part the expansion of the cortical wave that is spreading contemporaneously through locally-connected cortical cells

PART III RETENTION OF CONSCIOUSNESS

In a normal transition to NREMS the volley of synchronous spindle bursts that marks the onset of stage 2 NREMS overwhelms the normal firing pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 137

of thalamocortical cells preventing their relay of afferent sensory signals and inducing a loss of consciousness21 But the loss of consciousness cannot be timed precisely using cortical EEG the thalamus is too remote for the onset of spindling to be reliably detected by scalp electrodes39 In experiments with cats where electrodes could be implanted in the thalamus researchers found that spindling often reached peak levels of activity in the thalamus-a level of activity consonant with stage 2 NREMS-at a time when the cortical EEG was still showing intermittent desynchronizations a pattern characteristic of the drowsy stage 1 transition not a fully-established stage 2 NREMS episode4o

In other words there is a short period of time in which the synchronous rhythms of stage 2 NREMS are installed in the thalamus but not in the cortex where cortical neurons continue to depolarize in response to afferent sensory signals

T his finding suggests a possible explanation for the authors ability to retain consciousness while spindle bursts are sweeping through the LGN if he is able to extend the duration of this time lag between

the onset of spindling in the thalamus and spindling in the cortex if he is able to stimulate the visual cortices in such a way that they continue to depolarize then he may be able to keep on processing visual signals-to remain visually aware-even after the non-visual thalamus and non-visual cortex become entrained by synchronous sleep rhythms The authors induction technique includes several behaviors which are known to enhance the responsiveness of visual neurons-eye movements attentive fixation and an attitude of expectancy

Effects of eye movements and attention on the LGN Sustained convergence causes periorbital proprioceptors to send excitatory feedback directly to the LGN41 Also convergence further enhances the excitability of geniculate cells by stimulating the superior collicus (SC) which sends its own excitatory signals to the LGN42-43 These signals from the SC are known to selectively enhance the excitability of visual relay cells that represent the periphery of vision44 We know in the authors case that the SC is being stimulated because he is able to keep on fixating an ability which would normally be lost during the transishytion to NREMS45 The ability to fixate can be retained however if the SC is stimulated (even if stimulated during NREMS)46

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 138

Effects of eye movement attention and expectancy on the primary visual cortex The PET study of mental imagery by Kosslyn et al 3 showed that even a baseline resting state of relaxed immobile expectancy can generate signifishycant increases in neuronal activity in the primary visual cortices Further increases can be induced by sustained eye movements

A sustained convergence will release a stream of ponto-geniculo-occipital (PGO) waves These PGO waves called eye movement potentials or EMPs last only as long as the eye movement1747 whereas the PGO waves associated with rapid-eye-movement sleep (REMS) fire continually for the duration of the REMS episode Both REMS-related PGO waves and EMPs have the same desynchronizing effect on the visual pathways they move through the LGN depolarizing the thalamocortical cells which relay the signals to cortical neurons The responsivity of neurons in the primary visual cortices is enhanced by the stimulation of PGO waves 1747-49 If the passage of EMPs causes the genicushylate relay cells and their cortical targets to depolarize regularly then a volley of 4 spindle bursts moving through the same pathways will register as just another series of depolarizations in effect the spindle bursts are processed by the visual system as if they were sensory signals sent from the retina rather than an event stimulated by endogenous mechanisms

T he impact of eye movements and ftxation on the parietal visual cortex Convergence and attentive fixation will also enhance the responsiveness of light-sensitive parietal visual neurons (PVNs) in area PG of the

posterior parietal cortex 50 In experiments where monkeys are trained to fix their attention on a screen-and to keep on fixating even if no targets appearshythe excitability of these light-sensitive PVNs increases by as much as 350 51

52-53Responsiveness is also facilitated by the angle of gaze Also area PG is the first region in the visual pathways containing individual neurons with the capacity to respond to large bilateral stimuli moving in opposite directions along the central meridians of vision (opponent vector motion) 853-55 Facilitation of PVNs in area PG has the effect of sensitizing the subject to bilateral opponent vector motion and this is especially true if the movement appears in the periphery of the VE 8

Intracortical ampliftcation and feedback to the LGN When PGO waves and signals from the SC arrive in the primary visual cortex they may be relatively weak however weak signals can be amplified by reverberating in large networks

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 139

of cortical cells linked by local projection 56 There are nine times as many excitatory links among cortical cells as there are projections from the visual cortex to the LGN an imbalance which suggests leads Suarez Koch and Douglas to propose that geniculate input provides only a minor fraction of the excitatory input the majority originating in neighboring and recurrently connected cortical cells57 If the excitabiliry of cortical neurons is slightly higher than normal then this process of amplification may continue even after the LGN signals that initiated the reverberation are no longer being transmitted by the LGN ( a hysteretic mode of operation) 57

Feedback from hyperexcited cortical neurons will stream back to the LGN via corticogeniculate projections which outnumber geniculocortical projections ten-to-one One effect of this feedback is that the LGN is

able to absorb large amounts of information flowing back from the cortex 58

As signals reverberate back and forth in thalamocorticothalamic circuits a matching process takes place those geniculate relay cells that fire in patterns consistent with the firing patterns of active cortical cells will have their responshysivity enhanced while those geniculate cells that fire in patterns not consistent with cortical cells will be suppressed 59

Preservation of consciousness by selective facilitation of the visual pathways By combining all of the facilitatory effects produced by the authors eye movements and attentive fixation-(l) stimulation of the LGN by feedback from periorbital proprioception both directly and indirectly via the SC (2) the release of PGO waves (EMPs) that facilitate neurons in the LGN and primary visual cortex as they pass (3) the facilitation of the primary visual cortex by a state of relaxed immobile expectancy (4) attentive fixation and angle of gaze that facilitate PVNs in area PG (5) intracortical amplification of signals received from the LGN and (6) corticogeniculate feedback that stimulates the LGN-we delineate a circuit of enhanced excitability that extends from the LGN through the post-geniculate visual heirarchy to area PG where signals are integrated into representations of objects

The hyperexcitability of neurons all along the post-geniculate visual pathways creates conditions in the visual cortices which are similar to those present during EEG-desynchronized states of waking and REMS Therefore neurons in the visual pathways are too excitable to be entrained by synchronous bursting

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 140

patterns when spindle waves move through them instead the spindle bursts stimulate visual neurons to depolarize and then recover as happens in response to afferent sensory signals during waking states It is important to note that for this to occur none of the constituent neuron assemblies is required to perform an abnormal operation the abnormality is a function of the authors intent to activate contemporaneously neuron assemblies that would not normally be co-activated

PART IV HYPNOTIC ANALGESIA

Manipulation of spatial attention as a method for alleviating pain sensations In a theoretical article on the neurophysiology of hypnosis Crawford and Gruzelier60 propose that variations in hypnotizability are function of variability in the efficiency of the frontolimbic (anterior) attentional system in humans high-hypnotizables are better able to sustain focused attention on a task and to ignore extraneous stimuli than are low-hypnotizables

I na related empirical study that compares the use of attention by subjects with high versus low hypnotizability Crawford Brown and Moon61 report that highly hypnotizable persons continue to show physiological reactivity

while cognitively not perceiving the painful stimuli Through disattentional processes they can dissociate themselves from the awareness of pain The authors phosphene induction behaviors-and the cutaneous analgesia he experishyences-appear to involve the same kind of behaviors that is a mobilization of frontolimbic attention used to withdraw attention from external stimuli and to concentrate it on internally-generated phosphene images This suggests the hypothesis that the mechanisms that generate phosphenes might also produce hypnotic analgesia There are several ways that visual signals and pain signals might interact to produce this analgesia

Competition between pain and vision signals for limbic registration The fully-developed sensation of pain requires integration of rwo kinds of informashytion Signals that encode the location and intensity of a noxious stimulus (nociceptive signals) are relayed via the thalamus to the somatosensory cortices which registers only the sensory-discriminative aspects of pain perception62 before reaching consciousness the nociceptive signals must be sent to the limbic

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 141

system where they are linked with signals from long-term memory that encode the affective significance the stimulus has acquired for that individual Studies of brain metabolism show this linking of somatosensory information with limbic associations takes place in the anterior cingulate (CG) and anterior insula62-64

PET studies also show that the anterior CG is activated when subjects shift their spatial attention in response to expectations as to where

66stimuli will next appear65- This is precisely what takes place during the state of immobile expectancy that induces phosphenes Since visual signals and nociceptive signals both require limbic enhancement which is only possible if they get access to the anterior CG there might be conditions in which the two types of afferent sensory signals have to compete for that access In a theoretical article on the mechanisms of attention Posner and Rothbart67

propose that visual signals can interfere with nociceptive signals by blocking access to the anterior CG As behavioral evidence they cite studies showing that when young infants make distress calls they can be distracted by the presentation of a new visual stimulus We have shown the evidence of such control at about three months Orienting to visual events can be employed to quiet or calm negative vocalizations However the distress appears to be maintained and reappears when the infants attention to the stimulus is reduced Caregivers also report the use or visual orienting to block overt manifestations of distress at about this age 67

The effects of disattention on the somatosensory cortices If there is a competition between visual signals and nociceptive signals for access to the anterior CG it is likely that the competition will be affected by the relative volume of signals received A recent study suggests that focusing attention on internally-generated visual stimuli may reduce the number of nociceptive signals relayed by the somatosensory cortices Drevets Burton Videen Snyder Simpson and Raichle68 have shown that the mere anticipation of a touch at a specific cutaneous site increases the flow of blood to those cortical somatosenshysory neurons that are linked with that site where touch is expected and decreases the flow of blood to neurons linked with sites where touch is not expected In this experiment the researchers designated touch as the behaviorally significant sensory stimulus but their findings suggest that the outcome could be reversed if the instructions were reversed if subjects were

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page J42

instructed to direct attention away from a cutaneous site where a noxious stimulus was being applied if they were instructed to relax close their eyes and concentrate on the play of phosphenes in the visual field as the behaviorally significant sensory stimulus then it would be reasonable to expect that the flow of blood would decrease to the somatosensory neurons linked with the cutaneous stimulus and that the flow of blood would increase to the visual cortices The decrease in blood flow to somatosensory neurons implies less neuronal activity which implies that fewer signals are being sent forward to the anterior CG than would have been sent if instead the subject were treating the touch as the behaviorally significant sensory stimulus If fewer pain signals arrive at the anterior it is reasonable to infer that the conscious experience of pain will be muted by the diversion of attention to internal visual stimuli

Differential impact of sleep rhythms in the visual and nonvisual thalamus There is another mechanism that might also contribute to the analgesic effect of inducing sleep rhythms PET studies show that

the thalamus is involved in the relay of nociceptive signals to the cortex63 although some confusion remains about which kinds of signals are relayed by which subregions in the thalamus62 One thalamic site clearly identified by anatomical studies as a relay for nociceptive signals is the ventroposterior lateral nucleus (VPL)69 If synchronous sleep rhythms are active in the thalamus we can reasonably expect that the VPL will itself be entrained by synchronous oscillations and that it will relay the sleep rhythms to somatosensory cortices Relay neurons in the VPL are not stimulated by feedback from eye movements and fixation as are relay neurons in the LGN which suggests that sleep rhythms may impede the relay of nociceptive signals via the VPL but not the relay of visual signals via the LGN

Brain waves associated with anesthesia and NREMS The hypothesis presented here-that consciousness can be preserved despite the presence of NREMS activity-is consistent with a recent report that the kinds of fast brain waves which are normally associated with conscious states are also present during NREMS and anesthesia two states which were thought to involve minimal brain activityJo Another recent study found that there is a close resemblance between the slow brain waves that appear during NREMS and those that appear during certain types of anesthesia71

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 143

bull bull bull

CONCLUSION

In this paper we have presented evidence supporting the hypothesis that phosphene images can be generated as an epiphenomena of thalamic spindle bursts and delta wave activity normally associated with NREMS The prereqshyuisites for inducing these sleep rhythm phosphenes are relaxed immobile expectancy sustained convergence and attentive fixation of an undifferentiated visual field Our hypothesis provides a necessary and sufficient explanation for the authors induction of phosphenes and perhaps also for the generation of phosphenes reported to appear spontaneously during the drowsy transition to sleep (hypnagogic states) during sensory deprivation or during certain kinds of prayer or meditation all of which involve a similar state of relaxed immobile expectancyJ2

CORRESPONDENCE Philip T Nicholson bull 52 Norfolk Road bull Chestnut Hill MA 02167

REFERENCES amp NOTES

1 M 1 Posner Modulation by Instruction Nature 373 (1995) pp 198-199 2 J Reissenweber E David amp M pfotenhauer Investigations of Psychological Aspects of

the Perception of Magnetophosphenes and Electrophosphenes Biomedizinische Tecknik 373 (1992) pp 42-45

3 S M Kosslyn W L Thompson 1 J Kim amp N M Alpert Topographical Representations of Mental Images in Primary Visual Cortex Nature 378 (I995) pp 496-498

4 P E Roland amp B Gulyas Visual Memory Visual Imagery and Visual Recognition of Large Field Patterns by the Human Brain Functional Anatomy by Positron Emission Tomography Cerebral Cortex 51 (1995) pp 79-93

5 H Benson The Relaxation Response (Morrow New York NY 1975) 6 ] H Schultz amp W Luthe Autogenic Training a Physiological Approach to Psychotherapy

(Grune amp Stratton New York NY 1969) 7 E Jacobson Progressive Relaxation (University of Chicago Press Chicago IL 1938) 8 M A Steinmetz BC Motter C] DuffY amp V B Mountcastle Functional Properties

of Parietal Visual Neurons Radial Organization of Directionalities Within the Visual Field Journal ofNeuroscience 71 (1987) pp 177-191

9 R R Edelman Magnetic Resonance Imaging of the Nervous System Discussions in Neuroscience 71 Elsevier Science Amsterdam (I990) also J H Newhouse amp ] I Wiener Understanding MRI 1st Ed (Little Brown Boston MA 1991)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 144

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

black in front of their minds eye (ie not to have any visual imagery)3-4 A cortical EEG confirmed that all subjects had predominant alpha-rhythm as is expected when subjects are relaxed with eyes closed When they analyzed the results the Kosslyn team was surprised to find that the baseline resting condition generated a significant increase in neuronal activiry in the primary visual cortex an increase that antedated the performance of the assigned visual tasks The similarities berween the behaviors used as the baseline resting condition in the PET studies and the behaviors used by the author to induce phosphenes suggests that similar mechanisms may be involved In this paper we hope to identifY those mechanisms

METHODS

The author a fifty-year-old medical writer with no history of drug or alcohol abuse uses autohypnosis to disperse pain during dental or medical procedures to relieve muscle tension headaches to warm his extremities

and to induce sleep His method of autohypnotic induction resembles the generic relaxation response popularized by Benson but involves a more active manipushylation of eye position and attention 5 To begin inducing phosphenes the author lies on his back closes his eyes takes slow deep rhythmic breaths and gives himself silent instructions used in autogenic training such as let yourself relax or concentrate on the breathing6 If body or mind resists relaxing he tries progressive relaxation techniques which involve tensing and relaxing the large muscles of the body in systematic sequence

Once noticeable relaxation is present the author begins to manipulate eye position to accelerate dissociation He converges his eyes with enough force to elicit a continuing sensation of fullness or pressure in the eyeball At the same time he tests which of rwo different eye positions produces the strongest feeling of having the attention hone in or lock in on the fixation point at the center of vision (1) with eyes converged and slightly depressed as if focusing on the tip of the nose or (2) with eyes converged and elevated as if focusing on the forehead or crown If the eyes were opened in either of these positions they would produce a non-fused image of the external world (With long practice the response is conditioned so that a less forceful convershygence is needed to produce the same effect)

Subtle Energies 6- Energy Medicine bull VoLume 7 bull Number 2 bull Page 113

I n addition to manipulating eye position the author focuses all his attention on the fixation point at the center of the visual field even though at this early stage in the phosphene induction process the visual field remains

empty of everything except random metabolic discharge referred from the retina-the eigengrau or self-generated gray light When the attention is fixated strongly enough the author experiences auditory feedback-a distincshytive tinnitis cerebri that seems part sound but also part vibration This sensation originates inside the lower rim of the skull at about the level of the ears and feels as if it radiates upward on both sides It sounds like bird wings fluttering the sputtering of an open wood fire or a dull buzz The reader can experiment with eliciting a version of this same tinnitis by staring intently at some external object located just beyond the reach of an extended arm With practice this tinnitis can be sustained for long intervals and used as a feedback signal to mark the efficiency of dissociation Long practice also conditions this response so that a slight convergence of the eyes a straight-forward stare and fixed attention are sufficient to evoke the tinnitis and then the phosphenes The author continues the stereotyped eye movements and attentive fixation until phosphenes appear and for the duration of the phosphene displays

No less important than sustained convergence and attentive fixation is the ability to keep the level of arousal low and the mental field free of distractions The author remains passive and ready to acquiesce in whatever happens To minimize the distraction of unwanted thoughts images emotions itches or pains he uses a traditional meditation strategy-not attempting to resist distracting content but rather treating its arrival with indifference letting it drift freely in and out of consciousness This disengagement from potentially disruptive thoughts combined with steady breathing and the intense focusing of attention preserves equanimity and maintains a low level of arousal

Pain control requires adding another strategy In response to a painful stimulus the large muscles of the body usually tense involuntarily and fear of further pain breaks into awareness The author counters these instinctive and involunshytary reactions by deliberately posing the thought that the pain is not actually attached to the body that the pain can be given away by allowing it to flow out of the body and to disperse in all directions in which case the author need not take action in order to escape or avoid the pain This mental strategyshyin effect a deliberate abandonment of the normal vigilance which is oriented

Subtle Energies amp EnerfJ Medicine bull Volume 7 bull Number 2 bull Page 114

toward behaviorally significant external stimuli-results in a sudden preCIpIshytous drop in tension and restoration of the former relaxed state This reshyrelaxation occurs immediately after the muscles tense involuntary in response to the painful stimuli Keeping relaxed helps diffuse the pain sensations and the anxiety about pain The anticipation that relaxation (and the relief it brings) can be quickly restored after the next painful stimulation creates confidence that events are not out of control and that therefore it is not necessary to divert ones attention from the focus on the visual field that generates the phosphenes

The authors phosphene induction method closely resembles the behaviors used as the baseline resting condition in the PET studies except that in those studies subjects were not explicitly instructed to converge their eyes or to fixate their attention However the authors attempt to carry out their instructions-lying motionless with eyes closed and having it black in front of the minds eye results in his eyes focusing automatically on the near visual field an operation which requires some convergence (although not as much as the author would normally use) His attention also focuses automatically on the center of the empty visual field If the authors experience is typical then the two sets of behaviors may be virtually the same with differences being in degree not in kind

OBSERVATIONS

PHOSPHENE RECEDING ANNULI

The threshold sequence of phosphene images is illustrated in Figure 1 Just before the appearance of phosphene there is a fleeting sensation of a movement inward from 3600 of the peripheral visual field (VF)

as if a dark annular wave were moving through the dark background with so little contrast that it is almost imperceptible This annular wave suddenly illuminates while still in the far periphery of the VF (at about 80 - 60deg of isoeccentricity) presenting a bright thin phosphene annulus yellow-green in color that decreases in diameter at a constant rate preserving its annular symmetry until it disappears into the centerpoint after 4 seconds of elapsed time (estimated by counting 1001 1002 etc) There is an interval

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 115

0- 05 sec 10 sec 15 sec

20 sec 25 sec 30 sec

Figure 1 Schematic drawings ofreceding annuli phosphenes At first there is a sensation of movement inward from 360 0 in the periphery of vision then a bright thin yellowshygreen phosphene annulus sudden~y illuminates at about 80 60 of isoeccentricity The edges ofthe annulus are well-defined but more diJfose than this computer drawing program can depict-like a wellformed smoke ring The annulus preserves its symmetry as it shrinks steadio in diameter at a constant rafe offlow creating the illusion that it is receding toward the center of vision At 2 seconds the empty space inside the annulus fills abrupto with a disk ofbrighter phosphene At 4 seconds the image disappears into the centerpoint At 5 seconds another annulus sweeps into the periphery The author sees a total of4 receding annuli

of 1 second then the next wave appears at the periphery of the VE Midway in the trajectory-at 2 seconds-the empty interior of the annulus fills abruptly with a disk of slightly brighter phosphene A sequence of annuli usually terminates after 4 images although the number of annuli can be increased by diverting the attention for a moment and then refocusing

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 116

While the color of the annulus has remained the same over time the color of the filling-in disk changed after about two years of intermittent phosphene induction from yellow-green to blue The change began with tiny flecks of blue flashing amid the green just as the disk disappeared Over a period of several weeks the amount of blue expanded and appeared earlier in the fillshysequence Within a month the entire fill-disk was blue

The shrinking annuli create a psychological illusion of a ring of light receding toward a distant point in 3-dimensional space and pulling the attention into a vortex or paradoxically the same progression can create a sensation of falling backwards an illusory motion that resembles an effect produced by optic flow Motion in the visual periphery elicits in the stationary observer an illusion of self-motion (vection) indistinguishable from real motion The illusion of vection is compelling for it dominates contradictory proprioceptive signals For example subjects presented with optic flow consistent with backward self-motion perceive backward motion even if they ate actually walking forward 8

T he same receding annuli appear spontaneously as hypnagogic images while the author is reclining and waiting for sleep The receding annuli appear whenever the authors mind and body are relaxed his eyes closed

and his attention focused straight ahead-essentially the same behaviors used for self-hypnosis-but in the hypnagogic context virtually no effort is required the receding annuli feel as if they were released spontaneously not induced If the author is not relaxed or if he is distracted by a headache or importuning thoughts then the luminous receding annuli do not appear Instead the author loses consciousness abruptly at the onset of NREMS

AMORPHOUS EXPANDING PHOSPHENES

(A) loCAL RANDOMLY-DISPERSED EXPANDING WAVES Figure 2(A) illustrates one kind of amorphous phosphene mist that appears after the receding annuli sequence terminates These phosphenes are small amorphous swirls of yellowshygreen that coalesce suddenly at unpredictable locations in the VF and expand for a second or two then fade into the background There are often several images drifting in the visual field at the same time each in a different stage of evolution and the density of the phosphene seems to vary with some areas appearing thin and translucent others more opaque-like puffs of smoke that

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 117

10 seconds 15 sec 20 sec

25 Bee 30 sec 35 sec

expand and curl aimlessly then dissipate Because these waves are so unpredictable and formless the author is unable to predict the mean number of signals per episode the period between signals the site of entry or exit or to define a typical trajectory other than in the abstract generic manner used above The signal-to-noise ratio in these phosphenes is very low since phosphene stands out against the background there clearly is a signal but this signal presents so little pattern that it is essentially a form of phosphene noise These localized pulsations may continue for several minutes but usually within a minute or two they are superceded by the type of amorphous wave described next

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 118

Figure 2 [focing page Schematic drawings of of amorphous expanding phosphenes (A) Brief randomly-dispersed localized pulses These phosphenes are the first to appear after the receding annuli They coalesce at unpredictable locations in the IF expand asymmetrically for a second or two then dissipate into eigengrau before there is time to extend very for beyond their locus of origin (B) Periodic unidirectional amorphous expanding waves These phosphene waves enter the periphery ofvision from one hemifield presenting as a loosely-defined crescent (hemi-annular) cloud that mirrors the curvature of the peripheral rim The leading edge of the wave expands and flows across the vertical meridian into the opposite hemified swirling around the periphery curling inward and merging while at the same time the trailing edge ofphosphene dissipates rapidly in those regions over which the wave has already passed like mist or smoke evaporating in air The author is unable to time these waves but their duration fiels roughly the same as for receding annuli ie about 4 seconds Waves appear one after another in a cluster with a refractory period between clusters during which no waves appear After a prolonged session ofself-hypnosis the phosphene may not completely dissipate between successive waves in which case the residual phosphene accumulates in a vaguely-circular cloud shape with a small area its center that undergoes continual perturbation the phosphene pulls back leaving a small Mrk circle at the center of the cloud then fills back in then pulls away again ebbing and flowing in like manner until the cloud dissipates At this stage the image resembles an eye with a phosphene iris and a dark inner pupil (C) Twoshytone phosphene During a prolonged session the phosphene at the very center of the amorphous cloud becomes much brighter more fine-grained almost opaque with highly saturated color When a hole (pupil) appears in the center ofthe cloud forming an eyeshyimage the brighter phosphene becomes a thin bright rim lining the Mrk hole from this bright inner rim tiny promontories ofbright phosphene flare out into the Mrk hole twist and coil and collide with other flares forming webs and momentarily filling-in the Mrk hole or receding back into the rim The two-toned phosphene does not only appear in conjunction with the eye-shape clouds it also manifests at the center ofa variety ofelusive ever-changing shapes It is always restricted to the area offoveal vision

(B) PERIODIC UNIDIRECTIONAL AMORPHOUS WAVES These phosphene waves sweep in from one hemifield as shown in Figure 2(B) Often the wave has a vaguely crescent shape at the outset that conforms to the concave curvature of the peripheral VF then the crescent shape gives way as the wave expands rapidly in divergent directions flowing smoothly across the vertical meridian to envelop those regions of the VF that have not yet been illuminated As the leading edge of the wave expands the rear edges are already beginning to dissipate The swirling movement and the contraction of outer boundaries leaves a cloud of phosphene near the center of the VE This cloud may dissipate rapidly or it may persist for several seconds during which a pertur-

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 119

bation takes place at the center of the cloud the phosphene ebbs away from this region leaving a tiny dark hole then the phosphene fills back in then it ebbs and fills again-a fluctuation that continues as long as the phosphene cloud is visible During the perturbations the phosphene vaguely resembles the iris of a human eye with an interior dark space as its pupil This eyeshyimage is seldom symmetrical and its boundaries are always changing

(c) TWO-TONE PHOSPHENE When the phosphenes are induced over a prolonged period of time the phosphene in the central region representing foveal vision presents a more intensely bright more opaque (finely-grained) character than the rest of the cloud as shown in Figure 2(C) When this brilliant opaque phosphene appears as part of an eye-image it forms a thin rim surrounding the pupiL From this rim flares jut out into the dark pupil space coil about merge or recede back into the rim

The periodic unidirectional amorphous waves do not terminate after a stereoshytyped sequence they can be evoked over prolonged rime periods if the autohypshynotic behaviors are maintained The author is unable to retain the vision of these amorphous waves while simultaneously counting the number of seconds elapsed it is his impression however that the duration of amorphous expanding waves feels about the same as for receding annuli that is a duration of about 4 seconds per wave The amorphous waves usually appear in clusters followed by a refractory interval during which no phosphenes appear even if induction behaviors are sustained

PHOSPHENES SUPERIMPOSED ON ExTERNAL OBJECTS

The author can observe amorphous phosphene images with his eyes open if he is in a room dark enough that colors cannot be distinguished or if he is

in a lighted room but one where he can keep his eyes diffusely focused on a relatively undifferentiated surface such as a wall or ceiling with a light and uniform color and no distracting decorative adornments In open-eye viewings phosphenes appear as faint translucent waves of yellow-green mist

superimposed over the surface or in the dark space that fills the darkened room If the author attempts to focus on the features of external objects the phosphenes disappear

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 120

RECEDING ANNuLI EVOKED BY MAGNETIC REsONANCE IMAGING (MRI)

A s a patient undergoing an MRI scan the author observed an unusual sequence of receding annuli He was not relaxed as in a normal induction but rather anxious about his medical condition and about

being confined in the narrow MRI tube To keep calm he concentrated on breathing slowly and stared straight ahead While the sound of MRI machine was audible the author observed a stream of receding annuli that differed from the usual sequence (self-induced and hypnagogic) in three ways (I) the MRI annuli did not terminate at 4 cycles but continued for as long as the author kept his attention focused (2) the MRI annuli were only yellowshygreen in color even though in other inductions the fill-in disk had already changed from green to blue and (3) MRI annuli completed their trajectoshyries in half the normal time disappearing in 2 seconds instead of 4 An interval of 2 seconds between radio pulses is often selected as optimal interval for capture of the signals emitted by hyperexcited atoms in the subjects body

10during the precessional relaxation 9- These observations suggest that energy released in the wake of the radio bombardment during MRI moves through the LGN as a standing wave in the same way that spindle bursts move but that the 2-second duration of the MRI wave is not long enough to activate the neurons that generate a blue sensation

THE ANESTHETIC EFFECT ASSOCIATED WITH SELF-INDUCED

PHOSPHENES

On several occasions the author has preferred to undergo minor surgery without local anesthetic and to rely instead on autohypnotic analgesia-for example during extraction of an infected abscess from the back during laser surgery to

remove keloids and during the filllng of dental caries His experience on a recent occasion when a dentist had to abrade the surface of six teeth with damaged enamel in order to create a strong bonding surface are worth describing here because the experience implies that spindle waves can be induced even during a state of high physiological arousal For this appointshyment the author arrived in the office too late to hypnotize himself in advance

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 121

so he had to begin the normal induction procedures after the dental work was already underway

A s the dentist worked on the first tooth the author experienced apprehension sharp sensations of pain and an involuntary tensing of the large muscles of the body with each application of the drill As

the author kept his eyes converged and his attention focused on the center of the visual field the involuntary tensing in response to pain alternated with a precipitous relaxing of those same muscles immediately after the stimulus With the repeated relaxation came a sense of relief and of letting go that amelioshyrated the pain The pain-driven relaxation was much stronger than the relaxation that normally accompanies the authors self-induction of phosphenes and the alternation of a pain-driven tensing on one hand and the distancing effect of focusing attention on the visual field on the other hand resulted in a rapid dissociation from all external and internal stimuli including a signifishycant amelioration of painful sensations

Most striking is the fact that by the time the dentist reached the third toothshyafter only a few minutes of this pain-driven self-hypnosis-the author saw a normal sequence of 4 receding annuli followed by swirling clouds of amorphous expanding phosphene even though the dentist was still using the drill contemporaneously This experience suggests that thalamic sleep rhythms can be voluntarily induced even when the subjects level of physiological arousal is high

SIMILARITIES WITH ATTENTION-INDUCED PHOSPHENES

REpORTED BY OTHER OBSERVERS

Taxonomies of phosphene images always include examples of simple geometric phosphenes with circular or semi-circular shapes (disks annuli or crescents) as

14well as formless phosphene mists 11 - There are also a number of anecdotal accounts that are relevant for example Friedman an opthamologist who studied entoptic images by introspection describes a similar sequence of annuli induced by sustained inward concentration Circular waves of blue color may be seen in the dark by the dark adapted retina They start at the

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 122

periphery and move inward toward the macula as a concentrically contracting solid circle disappear at the macula and begin again at the peripheryl)

A valuable but often-neglected resource of information about phosphene imagery is presented in the literature of religious mysticism Many mystics reported having seen translucent colored lights while absorbed in prayer or meditation A list of descriptions excerpted from self-reports is presented in Table 1 (These excerpts are representative of phosphene images that appear during states of calm and inward-oriented concentration they do not include images associated with paroxysmal raptures) These phosphene images exhibit a relatively limited set of shapes and colors the shapes are either circular (eg rings disks wheels suns) or formless (eg mists snow smoke) and the colors are usually a variant of either green or blue The phosphene visions of mystics display shapes and colors that are comparable to the images described by the author this and the many similarities in the behaviors used to induce phosphenes suggest that both sets of phosphenes have a common etiology

DISCUSSION

Whether the author uses self-hypnosis to induce phosphenes or experishyences them as hypnagogic images the threshold sequence of receding annuli has the same characteristics In both these

instances the antecedent behaviors involve a state of low physiological arousal combined with mental withdrawal from external stimuli These parallels suggest the hypothesis that phosphene displays are related to sleep-wake transitions

PART I RECEDING ANNULI AND THALAMIC SPINDLES

Mechanisms controlling the transition from waking to NREMS Based on the work of several research teams16-20 a consensus scenario for the generation of NREMS has emerged In this scenario NREMS is the product of three brain rhythms that interact with each other in thalamocorticothalamic circuits During the drowsy transition to sleep which in humans is called stage l NREMS the low voltage activity in the cortical electroencephalograph (EEG) still shows a pattern of intermittent desynchronization The polarization of

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 123

Table I Excerpts from self-reports of light visions by religious mystics

HEBREW MYSTICS the appearance of the wheels was like the gleaming of beryl and the four had the same form

their construction being something like a wheel within a wheel Ezekiel like a dome shining like crystal spread out about their heads And above the dome something

like a rhrone in appearance like sapphire Ezekiel a round Iodder like a full sphere rolling back and forth before him bright blue R Abulafia A glowing light clear brilliance A purple light that absorbs all lights R Moses de Leon

HINDU AND BUDDHIST MYSTICS a perfectly round beautiful deep-blue shape of a size appropriate to the center of a mandala as

if exquisitely painted of extreme c14rity Tsong Khapa a luminous revolving disc studded with lights a lotus flower in full bloom Gopi Krishna both my eyes became cemered When this happened a blue light arose in my eyes like

a candle flame without a wick and stood motionless in the ajna chakra S Muktananda

MUSLIM MYSTICS [like] chandelierssublime lights [like] stars moon or the sun Sharafuddin aI-Maneri its color is deep blue it seems to be an upsurge like water foom a spring Najmoddin Kobra visualize yourself as lying at the bottom of a well [looking up at the light of the opening] and

the well in lively downward movement Najmoddin Kobra the color green is the suprasensory uniting all the suprasensories Alaoddawleh Semnani the light rises in the Sky of the hean taking the form of light-gilling moons Najm Razi

CHRISTIAN MYSTICS his own state at prayer resembles a sapphire it is as clear and bright as the sky Evagrius descending like a bright cloud of mist like a sun round as a circle Simeon Neotheologos saw something in the air near him He did not understand the rype of thing but in some ways

it appeared to have the form of a serpent with many things that shone like eyes although they were not eyes Ignatius of Loyola

the soul puts on a green amilia [cape worn on shoulders beneath armor] John of the Cross [the almilla is like a helmet which] coverS all the senses of the head of the soul It has one

hole rhrough which the eyes may look upwards John of the Cross a round thing about rhe size of a rixdaier all bright and clear with light like a crystal H Hayen I saw a bright light and in this light the figure of a man the color of sapphireblazing with a

gentle glowing fire the three were in one light Hildegard von Bingen saw a b14zing fire incomprehensible inextinguishable with a flame in it the color of the sky

Hildegard von Bingen saw placed beneath her fuet the whole machine of the world as if it were a wheel She saw herself phced

above it her eyes of contemplation magnetized towards the incomprehensible Beatrice of Nazareth I saw the eyes I do not know if I was asleep or awake Angela of Foligno kind of sunlit winged being like a childs head beneath two little wings Abbess Thaisia laquobullbull round patterns small circles would expand and eventually dissipate only to be followed by other small

circles of light Philip St Romain an extraordinary circle of gold light pulsating against a deep violet background There were

always four or fille As soon as one would fode another would appear Philip St Romain

middotItalics added to mark words referring to (l) rings appearing in sets of four (2) amorphous shapes such as clouds or flames (3) circular or eye-like shapes (4) colors from the center of the visible spectrum (gold yellow yellow-green green bluish green) and (5) colors from the lower end of rhe visible spectrum (blue purple violet)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 124

cell membranes (Vm) has already begun to drop (hyperpolarize) in the thalamic reticular nucleus (RTN) a thin sheath of GABAnergic inhibitory neurons that acts as a pacemaker When the Vm of RTN cell membranes drops to approximately V m -60 millivolts (mV) RTN cells stop firing single spikes which are associated with waking states and instead begin firing highshyamplitude 7-14 Hertz (Hz) spike-bursts These bursts wax and wane over 1 to 3 seconds-hence the name spindle -and recur at 3 to 10 seconds Spindle volleys are relayed across the cortical mantle by thalamocortical (TC) sensory relay cells In human studies the primary criterion for onset of the first fullyshyestablished episode of NREMS or stage 2 sleep is the presence of globalized spindles in the cortical EEG

When spindle bursts from the RTN stimulate TC cells to fire in synchrony this synchronous bursting pattern overwhelms the normal capacity of TC cells to relay afferent sensory signals The loss of consciousness at the onset of stage 2 NREMS is thought to be caused by this blocking effect 21

While the RTN is firing spindle bursts through the thalamus another process is activated in the cortex large numbers of cells across the cortical mantle begin to oscillate at a very low frequency laquo 1 Hz)

The cortical slow rhythm referred back to the thalamus via corticothalamic circuits intensifies the hyperpolarizing effect of the RTN spindle bursts on TC cell membranes When V m -75 mV the TC cells begin to generate their own intrinsic calcium currents which further increases hyperpolarization At V m -90 mV the RTN neurons stop firing spindle bursts The TC cells continue to fire low-threshold calcium spikes in patterns which are controlled by the cortical slow rhythm The interaction of these two oscillations generates the delta waves (1 to 4 Hz) which are associated with stage 2 NREMS

In a study of sleep rhythms using the cortical EEG Uchida Atsumi and Kojima found that the mean number of spindles required to induce delta wave activity (that is to induce Vm = -90 mY) is 478 plusmn 162 spindles (from 3 to 7 spindles)22 The mean number of spindles in a volley remains the same for a single individual over multiple trials

Based on the consensus scenario for generation of NREMS we can predict that a phosphene image generated as an epiphenomenon of a thalamic spindle

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 125

Table II Dara show rhe degree of correspondance berween rhe pulse panerns of rhalamic spindles based on intracellular research and rhe sparioremporal panerns of receding annuli phosphenes induced by rhe author using a rechnique of self-hypnosis

Receding annuli phosphenes Thalamic spindle bursrs

Mean number of signals 4 annuli 487 (plusmn 16) bursrs

Sparial exrension vs Thin band 1 - 3 seconds durarion of signal ( 05 -15 cm)

Periodicity of signals 5 seconds 3 - 10 seconds

Simultaneity in LGNs Yes Yes

Point of entry Peripheral VF Ventral amp lareral LGN

Trajecrory Bilareral concentric Unknown

Rare of flow Cons rant rare Unknown

Signal-ro-noise rario High High (shorr bursrs) (sharp brighr discrere)

Termination of sequence Mrer 4 signals Mrer 487 (plusmn 16) signals

will present the following characteristics (1) a high-definition burst-like signal (2) that recurs within 3 to 10 seconds (3) that follows a trajectory compatible with having entered the LGN from the RTN (4) that has a predictable mean for the individual subject and a range that falls somewhere between 2 to 7 annuli and (5) that the spindles will terminate automatically

The temporal patterns of receding annuli and thalamic spindle bursts are similar Table II illustrates the close match between the timing of receding annuli phosphenes and thalamic spindle bursts The most striking similarities are the mean number of signals required to induce termination (4 annuli versus 487 spindles) and the interval between signals (5 seconds for annuli versus 3shyto-lO seconds for spindle bursts) Neither alpha theta nor beta waves present this kind of stereotyped temporal pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 126

T he spatial features of receding annuli are functions of geniculate anatomy A spindle burst moving through the LGN to the cortex will acquire certain distinctive spatiotemporal characteristics because of the

unique curvilinear and laminar anatomy of the LGN A drawing of a macaque LGN based on a clay model constructed by Le Gros Clark23 is shown in Figure 3 The primate LGN is composed of six sheets of cells or laminae that fold over a central hylus In macaques the hylus rises steeply as it extends rostrocausally forming a high arch at the posterior pole in humans the hylus is much more shallow but the functional anatomy is thought to be essentially

23 24the same in both cases - The geometry of the arch forces each lamina to bend so as to constitute in effect one-half of a conical surface and each lamina with its hemi-conical shape contains visual relay cells representing the contralatshyeral half of the visual field (VF) Operating as a pair the complementary hemishycones of the right and left LGN form the functional equivalent of a single conical surface which represents the entire VE This conical geometry of the paired LGNs means a burst of otherwise formless excitation will acquire a distinctive shape as it propagates through the laminae of the LGN Imagine a horizontal section moving along the surface of a cone from base to apex that moving section forms an annulus that shrinks in diameter as it approaches the apex but retains its annular symmetry throughout its trajectory

Figure 3 also includes drawings that show how Connolly and Van Essen24

converted the 3-dimensional structure of lamina 6 the largest and most dorsal layer into a 2-dimensional map Connolly and Van Essen used data obtained by Malpelli and Baker25 to superimpose a grid that specifies the areas in lamina 6 that contain TC cells representing various degrees of isoeccentricity in the VE We will use this map at a later point to show how the movement of a spindle wave through a pair of LGNs correlates with what appears in the VE

The location of the RTN relative to the LGN is also shown in Figure 3 The RTN spindle pacemaker is a thin sheath of GABAnergic inhibitory cells that extends along the surface of the whole posterior ventral thalamus not just the LGN This extension brings the RTN into close proximity with the portion of the LGN (lateral wing) that protrudes out from the main body of the thalamus Some of RTN wraps around and beneath the ventral edges of the LGN26 The RTN comes closest to the LGN in two areas along the ventral edges of the longest laminae (lamina 6 and 1) and along the edge of the lateral

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 127

DORSAL POLE DORSALPOIEA B

L1 L4 L3 L

DORSAL POlE DORSAL POIE (FOVEA)

G LATERAL WING

25

DORSAL POL (FOVEA)

10 _DIAL

20 WING

~

wing These areas contain TC cells that represent the far periphery of the VE If a spindle burst enters the LGN at locations where laminae are in closest proximity to the RTN-along the ventral edges-then the discharge of TC cells will begin in the most ventral portions of the laminae the regions that represent the far periphery of the VE This matches the phosphene sequence observed by the author

Our hypothesis about how this proximity between RTN and LGN affects the trajectory of spindle waves is illustrated in Figure 4 We propose that it is not possible for the author to observe a thin annulus of phosphene sweeping in from all 3600 of the peripheral VF unless spindle bursts exhibit the following

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 128

Figure 3 [facing page Drawings of primate geniculate anatomy and functional anatomy relevant to the generation ofphosphenes (A) Anterior view ofa macaque monkey LGN based on a clay model reconstruction by Le Gros Clark 23 (B) Posterior view ofthe same model showing 6 laminae folded over a central hylus to form lateral and medial wings with the hylus arching steeply upward near the posterior pole to shape the laminae into layers of hollow half-cones nested together Note that the lateral wing of the LGN is slightly larger than the medial wing so that in situ the lateral wing protrudes out from the main body of the thalamus creating a small knob visible during dissection 26 (C) Schematic drawing of an oblique section through median axis (also adapted from Le Gros Clark13 showing how the laminae fuse together at the anterior pole The afferent ganglion cell axons that form the optic tract (OT) penetrate through the anterior surface to reach their target relay cells in the laminae (D) Drawing of the most dorsal lamina-layer 6--separated from the rest of the LGN The geometric shape is a hollow half-cone so that right and left LGNs placed back-to-back form in effect a single cone Note also the position ofthe RTN shown here as a striped bar relative to lamina 6 The position of the striped bar shows that the RTN makes direct contact with lamina 6 at the edge ofthe lateral wing and also along the ventral edges (E - F) Schematic drawings adapted from Connolly and Van Essen24 that show how a 3-dimensional lamina-lamina 6--can be transformed into a 2-dimensional triangular figure lamina 6 is removed and its wings unfolded (E) creating a slightly asymmetric triangular figure (F) which is adjusted to an oblong shape (G) in order to superimshypose a grid matrix with minimal distortion The grid plots locations of TC cells that represent various isoelevations and isoazimuths in the VF locations derived from the experimental observations published by Malpeli and Baker 25 Note the relatively large amounts of laminar surface allocated to central vision (0 0

- 30 0) as compared

to peripheral vision (30 0 - 80 0)

characteristics (1) Spindle bursts must move simultaneously through both geniculate nuclei This pattern of movement is consistent with anatomical studies in primates that found axonal projections linking the right and left RTNs27-28 and with experimental studies in cats that found spindles appearing simultaneously in both right and left thalami 29 (2) Spindle waves must enter the ventral edges of the LGN first and move ventrodorsally in a highly coherent pattern-moving in effect as a standing wave This pattern of movement is consistent with in vitro experiments using sagittal slices from a ferret LGN where spindle waves originated spontaneously at the edge of a slice in an area which contains cells that represent peripheral vision then propagated toward that area of the slice containing cells that represent central vision in the ferret 3o

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 129

VF

PG BIlateral receptive lleJd of PVN YI(j Inward dmKooflality Adapled

0-- from Mortgr at at (1987)

V1

ibull t bull

RTN t t t t t t 1middot3 SECOlO BURSTS OF 7middot14 HZ SPiKES RECURRNG EVERY 3 10 SECONDS

To our knowledge the LGN is the only anatomical structure in the visual system that has the capacity of passively forcing a wave of excitation to flow across a conical surface thereby generating the sensation of a phosphene annulus that retains its symmetry as it shrinks in diameter The retina has a circular anatomy but it is not likely that the mechanical deformation of the retina would produce a wave that began simultaneously in all 3600 of the retinal rim nor that the symmetry of annular wave would be preserved as it flows inward toward the foveal region

The hypothesis presented here-that there is a structure in the visual system that imprints a conical shape on standing waves that move through it-explains

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 130

Figure 4 facing page Schematic drawing of contemporaneous events in selected regions of the visual processing hierarchy (A) The left and right RTNs fire spindle bursts simultaneously (B) The bursts pass through the right and left geniculate laminae as standing waves of depolarization entering from the ventral edges and moving ventrodorsally in parallel In order for the phosphene annulus to appear to be flowing at a constant rate the spindle wave flowing through the LCN must expand in width as it ascends ventrodorsally so that by the time the fill-in disk appears-when the center 30deg of the VF is covered by the phosphene annulus-the spindle wave must have expanded enough to activate relay cells in the most dorsal 50 of lamina 6 (C) Signals representing two complementary hemi-annuli are kept separate in the primary visual cortices (area VI) (D) Signals representing the two hemi-annuli are integrated into signals of a single annulus when they reach area PC in the posterior parietal cortex where the receptive fields of single parietal visual neurons have the capacity to register bilateral signals that exhibit opponent vector movement (that is signals converging from opposite directions along the central axes-as if an object were moving away from the viewer)46 Neurons in area PC also integrate wavelength (color) signals from the extrastriate visual pathway with signals about brightness motion and depth from the parietal visual pathway to compose a representation of an object in space-in this case of an annulus that appears to recede 32

the authors experience during MRI when he observed a continuous succession of receding annuli every 2 seconds in this view the energy of the electroshymagnetic bombardment when released during precessional relaxation flows through the geniculate laminae in the same way that the RTN spindle bursts do that is as a standing wave and thus the visual epiphenomenon is the same in both cases if the subject keeps the eyes focused straight ahead and the attention fixated In a study of phosphenes evoked by electricity in conjunction with hallucinogenic drugs Knoll Kugler Hofer and Lawder found that each subject sees specific kinds of phosphene at different frequencies and that these frequency-specific images are stable enough to be reproduced after six months31

They conclude that the tunability of the electrical stimulation frequenshycies within the EEG range to various definable phosphenes requires the existence of a resonance system One mechanism contributing to that resonance system may be the functional anatomy of the LGN

The colors of receding annuli as functions of geniculate laminar anatomy The colors of receding annuli phosphenes are consistent with the patterns of discharge spindle waves can be expected to stimulate as they move through

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 131

geniculate laminae As shown in Figure 5 the six laminae differ (1) in the types of wavelength signals relayed (2) in physical size and (3) in the area of the VF represented 24-25 Only 4 out of 6 laminae Cparvocellular layers 3shy6) contain TC cells that relay wavelength signals the other 2 laminae (magnocellular layers 1 and 2) do not encode wavelength Among parvocelshylular laminae only lamina 6 the longest and most dorsal layer contains TC cells that can represent the far periphery of the VF (from 800 to 50deg of isoeccenshytdeity) therefore when the spindle wave enters the peripheral VF only those wavelengths relayed by lamina 6 will participate in composing a cortical lightness record (See Zeki)32

I n lamina 6 ganglion cell axons arriving from the retina carry two kinds of wavelength signals (1) center-ON signals from medium-wavelength cones (M-cone center-ON) and long-wavelength cones (L-cone centershy

ON)33-35 Using the cone spectral sensitivity curves (adapted from Marks et al 36) we average the wavelengths that elicit maximal responses for M-cones (535 nanometers) and L-cones (520 nm) which yields a mean wavelength value of 550 nm In humans this wavelength generates a sensation of green or yellowshygreen the sensation observed by the author

As the spindle burst moves ventrodorsally it reaches the dorsal areas in the geniculate laminae which contain TC cells representing the central 0deg to 20deg of isoeccentrieity in the VE All 4 parvocellular laminae have TC cells which are potentially capable of representing this central region of vision but the authors observation that the color of the filling-in disk changed from green to blue implies that in the early years of phosphene induction the spindle wave must have remained close to the surface of the LGN stimulating only laminae 5 and 6 which generates a sensation of yellow-green When the fill-in disk was observed to change color from green to blue the spindle wave must have been rechanneled so that it began to penetrate below laminae 5 and 6 and to activate laminae 3 and 4 the only laminae that relay blue-sensitive signals (Sshycone center-ON signals)3 In light of the authors MRI experience it seems likely that a spindle wave requires a minimum of 2 seconds to reach the blueshysensitive cells of laminae 4 therefore during MRI when the receding annuli disappeared after 2 seconds half the normal duration the fill-disk had a green color even though it had long since change to blue in other induction settings with a 4-second trajectory

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 132

A REPRESENTATION OF THE VISUAL FIELD IN EACH LAMINA

orooqUtftc O-u OCIJ1SALfIOLI (I01flAj

0

10

20

30

40 n50 Of

60

70

20 loO 1Mgr_ II~ o UIpoundAS65 mn1MY-o actlvncL ~~~r

Jll-COMcetlImiddot~

II LAYERSU 3 GatQYancetl~ (1) ucon ceom-oyenF (2)l~cen()FF 3) ~ cenloH

II~ cng1loqctWIIIfNla

iICINe -- (t81Otdb1t1d~OH (2)~

80

B CONE SPECTRAL SENSITIVITY CURVES

S-COHS

WAVIlLllNG1llS OF UGHT IH NANOMllTERS (NM)

Figure 5 Phosphene color as a function of ganglion cell distribution in parvocellular laminae (Aj Schematic drawing ofthe proportion ofthe VF represented in each laminae The proportions shown here are based on the work of Connolly and Van Essen24 The

far periphery of vision (50 0 to 80 0 of isoeccentricity) is represented in only two laminae-laminae 1 and 6-and of these two only lamina 6 is a parvocelLular lamina capable ofencoding wavelength signals Therefore only those wavelengths relayed by lamina 6 will participate in forming a cortical lighmess record for the far periphery of the VP (B) Cone spectral sensitivity curves (adapted from Marks et al)36 Using these cone sensitivity curves we can estimate the sensation stimulated by a spindle wave moving through lamina 6 by averaging the wavelengths that elicit maximal responses for M-cones (535 nanomeshyters) and L-cones (520 nm) which yields a mean wavelength value of550 nm In humans this generates a sensation of green or yellow-green the sensation observed by the author when the receding annulus enters at the far periphery of the VP For a calculation of the cortical lightness record when a spindle wave moves through 20deg to 0deg ofthe VF stimulating all 4 parvocelfular laminae see the text and Figure 6

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 133

Once the spindle wave penetrates to laminae 3 and 4 it may activate all 4 parvocellular laminae stimulating TC cells to send contradictory wavelength signals for the same retinotopic location the signals sent from laminae 4 and 3 will encode blue light (S-cone center-ON plus M-cone center-OFF and Lshycone center-OFF) while the signals sent from laminae 5 and 6 encode yellowshygreen light (M-cone center-ON plus L-cone center-ON) This kind of contrashydiction does not occur in normal retina-based perception where light energy striking the retina is structured by the retinas center-surround and colorshyopponent organization to encode only one set of wavelength signals for each spatial locus 32 In Figure 6 we estimate the cortical lightness record that results when contradictory wavelength signals compete to be represented in consciousshyness Our calculations suggest that the outcome will be a mean wavelength which in humans elicits a dark blue or violet sensation

PART II AMORPHOUS PHOSPHENES amp THALAMIC DELTA ACTMTY

M echanisms controlling the transition from spindle bursts to delta activity In the consensus scenario for the generation of NREMS16-20 we noted that the RTN shifts to firing spindle bursts

when polarization of thalamic cell membranes drops to V m = - 60 mV At the same time cortical cells begin oscillating with a synchronous slow rhythm laquo 1 Hz) Both processes further decrease the Vm of TC cell membranes When Vm = - 75 mY TC cells begin to generate their own intrinsic calcium currents which also decreases V m At V m = - 90 mV RTN neurons stop firing spindle bursts At the same time the TC cells begin firing low-threshold calcium spikes in alternation with after-hyperpolarizations (LTS-AHP) Because sensory relay neurons in the LGN are not linked to one another by locally projecting axons the firing of one TC cell does not excite its neighbor However a lack of local connectivity does not mean that TC cells occupying the same laminae release their AHP-LTS calcium spikes in a random distribshyution rather spikes are released simultaneously by groups of cells in synchrony with the advent of the cortical slow wave In effect the distribution of LTSshyAHP spikes firing in the LGN is determined by the spatial propagation of the cortical slow wave Thus the delta wave (1 to 4 Hz) activity detected by cortical EEG during NREMS is a product of the interaction between the AHP-LTS calcium spikes released by TC cells and the cortical slow rhythm

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 134

CORTICAL PROCESSING OF CONTRADICTORY

WAVELENGTH SIGNALS

KEY _ Cells firing

cJ Cononol firing

Assume that as a spind6e wave moves through the LGNlt fires simultaneously aU the TC cells that represent a particular reUnoshytopic locus (x y) in each of the six laminae As a result cortical cells engaged In the higher level processing of visual signals will receive more wavelength signals representing retina locus (x y) than are generated by normal perception laquo and some of these afferent wavelength signals may contradict other signals arriving simultaneously

CORTICAL LIGHTNESS RECORD SlgnalSell

Intemal contradictions not congruent wilt pre

SmiddotON eristing neuron neta

s bullbull M-ON LmiddotON

3 bullbull M-OFF + L-OFF

a-ON 12

ROD-ON

No Internal eonlradlemiddot

--------1I =~8b~~~~~~~t signals

3+4

~ --OFF Excludes 6 Of 7 $J9n18

1+2 B-ON I

IWmiddotHmiddotI Signal Sell

1111111 No Intern1 conlrfldlcshy lion

Exelvdta 4 out of 7 efshy

bullbullbull bullbullbull ferant signals

No Intern1 contradic_ tionnee S-ON BshyOH and ROO-ON can all be coacllve at low lImlnance levels nef Ihe rod-eone break

ExchJde$ only 2 Ollt of 7 afferent signals

Figure 6 Selection of competing wavelength signals based on neuronal group selection This thought experiment is based on Edelman sconcept ofneuronal group selection 73 We assume that all possible combinations ofsignals will form sets and that all signal-sets will compete to make the most efficient match with pre-existing neuromd networks that have been forged over years ofnorma reti1U1-based perception We also assume that pre-existing neural networks are most likely to expedite those sets that satisfY 2 criteriI (J) the signals in a set do not contradict each other and (2) fower signals are excluded than in the other sets that satisfY the first criterion In our analysis Set 4 wins the competition because it does not contain internal contradictions and excludes fower signals (2 out of 7) than Set 3 excludes (4 out of7) It is not an internal contradiction that Set 4 contains both rods and cone Signtlls in normal retina-based perception when luminance levels approach the rod-cone break S-cone center-ON receptors send signas as do rod receptors and there is even evidence that rod activity may actually drive S-cone activity even after luminance levels foIl below the rod-cone break74 To calculate the cortical lightness record for Set 4 we average the wavelength that elicits maximal responses foom rods (511 nm) and for Sshycones (430 nm) which yields a mean wavelength of 470 nm which in humans results in a dark-blue or violet sensation

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 135

The cortical slow rhythm is an example of a generic pattern of neuronal excitashytion that occurs in large networks of neurons linked by local projections A recent experiment by Maeda Robinson and Kwana38 shows that networks of locally-connected neurons spontaneously generate periodic synchronized bursts of calcium transients that propagate across the network in an expanding spatial wave a pattern that represents a stable mode of firing towards which these neuronal networks relax following perturbations for example by electronic stimulation or by drugs Understanding the characteristics of these waves is an important prerequisite to understanding the mechanisms that produce the amorphous phosphene images as a visual epiphenomenon

To study the spontaneous periodic synchronized bursts the researchers prepared cultures of dissociated cortical neurons and allowed them to mature for several days in vitro (DIV) After 3 to 4 DIV when concenshy

trations of extracellular magnesium were low electrodes began to detect spontaneous synchronized bursts of low frequency calcium transients (between 01 and 1 Hz) that originated in different locations on the sheet every 10 to 20 seconds and spread across the sheet of cells at a relatively slow speed averaging 50 mmsecond The researchers could not predict where a wave would originate or where it would expand rather the initiation and expansion of waves was generated by spatial and temporal summation of a continuous random background of synaptic inputs including miniature spontaneous synaptic events but the pattern was not random since waves propagated sequentially from electrode to electrode as each local group of neurons charges up its neighboring nontefractory areas rather than in a random sequence of regions38

The excitability of the cells in the sheet determines the probability first that there will be a synchronous burst and second that it will spread in a particshyular direction Cells become more excitable as the cultures mature which means the refractory intervals between successive bursts were much shorter in mature cultures (gt 30 DIV) than in early cultures laquo 7 DIV) Some cells became so insensitive to inhibition that they continued to fire bursts even when extracellular concentrations of magnesium were relatively high Finally there were refractory periods of 5 to 10 seconds during which no bursts occurred even when an electrical stimulus was applied This refractory interval for cultured networks is slightly longer than the refractory interval observed of the cortical slow wave in vivo which 25 to 4 seconds 18- 19

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 136

Based on the observations about cortical slow waves we can predict that phosphenes generated as epiphenomena of delta wave activity will present the following signal characteristics (1) signals that appear at unpredictable locations in the VF (2) signals that expand and diverge asymmetrically following unpredictable trajectories which may encompass large areas of the VF (3) signals that move relatively slowly (50 mmsec) (4) signals that recur with a period of 2 to 4 seconds reflecting entrainment by the cortical slow wave (5) signals that do not terminate automatically after a predictable number of cycles

The spatial patterns of phosphene mists and thalamic delta waves are similar The spatiotemporal characteristics of amorphous phosphenes match the pattern of wave propagation associated with periodic spontashy

neous synchronized bursts in large neuron networks the amorphous phosphenes enter the visual field at unpredictable locations expand and diverge asymmetrically with a slow steady rate of flow follow trajectories that are unpredictable and exhibit a refractory interval The amorphous mists do appear to have a periodicity although the author is unable to sustain the vision while also counting the seconds therefore he is unable to determine if it compares to the period of the cortical slow wave (25 to 4 seconds) but his impression is that it feels roughly the same as as with receding annuli which recur at 5 seconds Also the refractory interval feels as if it decreases as the induction session is extended These similarities suggest that the amorphous phosphenes are generated by stage 2 NREMS delta wave activity which is an activity governed by the reverberation of the cortical slow wave in thalamoshycorticothalamic circuits The cortical slow wave is referred to the LGN where it modulates the firing of visual relay cells in the laminae and since relay cells do not have local dendritic connections the expansion of a wave of depolarshyizations moving from one relay cell to the next across in the laminar surface will mirror at least in part the expansion of the cortical wave that is spreading contemporaneously through locally-connected cortical cells

PART III RETENTION OF CONSCIOUSNESS

In a normal transition to NREMS the volley of synchronous spindle bursts that marks the onset of stage 2 NREMS overwhelms the normal firing pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 137

of thalamocortical cells preventing their relay of afferent sensory signals and inducing a loss of consciousness21 But the loss of consciousness cannot be timed precisely using cortical EEG the thalamus is too remote for the onset of spindling to be reliably detected by scalp electrodes39 In experiments with cats where electrodes could be implanted in the thalamus researchers found that spindling often reached peak levels of activity in the thalamus-a level of activity consonant with stage 2 NREMS-at a time when the cortical EEG was still showing intermittent desynchronizations a pattern characteristic of the drowsy stage 1 transition not a fully-established stage 2 NREMS episode4o

In other words there is a short period of time in which the synchronous rhythms of stage 2 NREMS are installed in the thalamus but not in the cortex where cortical neurons continue to depolarize in response to afferent sensory signals

T his finding suggests a possible explanation for the authors ability to retain consciousness while spindle bursts are sweeping through the LGN if he is able to extend the duration of this time lag between

the onset of spindling in the thalamus and spindling in the cortex if he is able to stimulate the visual cortices in such a way that they continue to depolarize then he may be able to keep on processing visual signals-to remain visually aware-even after the non-visual thalamus and non-visual cortex become entrained by synchronous sleep rhythms The authors induction technique includes several behaviors which are known to enhance the responsiveness of visual neurons-eye movements attentive fixation and an attitude of expectancy

Effects of eye movements and attention on the LGN Sustained convergence causes periorbital proprioceptors to send excitatory feedback directly to the LGN41 Also convergence further enhances the excitability of geniculate cells by stimulating the superior collicus (SC) which sends its own excitatory signals to the LGN42-43 These signals from the SC are known to selectively enhance the excitability of visual relay cells that represent the periphery of vision44 We know in the authors case that the SC is being stimulated because he is able to keep on fixating an ability which would normally be lost during the transishytion to NREMS45 The ability to fixate can be retained however if the SC is stimulated (even if stimulated during NREMS)46

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 138

Effects of eye movement attention and expectancy on the primary visual cortex The PET study of mental imagery by Kosslyn et al 3 showed that even a baseline resting state of relaxed immobile expectancy can generate signifishycant increases in neuronal activity in the primary visual cortices Further increases can be induced by sustained eye movements

A sustained convergence will release a stream of ponto-geniculo-occipital (PGO) waves These PGO waves called eye movement potentials or EMPs last only as long as the eye movement1747 whereas the PGO waves associated with rapid-eye-movement sleep (REMS) fire continually for the duration of the REMS episode Both REMS-related PGO waves and EMPs have the same desynchronizing effect on the visual pathways they move through the LGN depolarizing the thalamocortical cells which relay the signals to cortical neurons The responsivity of neurons in the primary visual cortices is enhanced by the stimulation of PGO waves 1747-49 If the passage of EMPs causes the genicushylate relay cells and their cortical targets to depolarize regularly then a volley of 4 spindle bursts moving through the same pathways will register as just another series of depolarizations in effect the spindle bursts are processed by the visual system as if they were sensory signals sent from the retina rather than an event stimulated by endogenous mechanisms

T he impact of eye movements and ftxation on the parietal visual cortex Convergence and attentive fixation will also enhance the responsiveness of light-sensitive parietal visual neurons (PVNs) in area PG of the

posterior parietal cortex 50 In experiments where monkeys are trained to fix their attention on a screen-and to keep on fixating even if no targets appearshythe excitability of these light-sensitive PVNs increases by as much as 350 51

52-53Responsiveness is also facilitated by the angle of gaze Also area PG is the first region in the visual pathways containing individual neurons with the capacity to respond to large bilateral stimuli moving in opposite directions along the central meridians of vision (opponent vector motion) 853-55 Facilitation of PVNs in area PG has the effect of sensitizing the subject to bilateral opponent vector motion and this is especially true if the movement appears in the periphery of the VE 8

Intracortical ampliftcation and feedback to the LGN When PGO waves and signals from the SC arrive in the primary visual cortex they may be relatively weak however weak signals can be amplified by reverberating in large networks

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 139

of cortical cells linked by local projection 56 There are nine times as many excitatory links among cortical cells as there are projections from the visual cortex to the LGN an imbalance which suggests leads Suarez Koch and Douglas to propose that geniculate input provides only a minor fraction of the excitatory input the majority originating in neighboring and recurrently connected cortical cells57 If the excitabiliry of cortical neurons is slightly higher than normal then this process of amplification may continue even after the LGN signals that initiated the reverberation are no longer being transmitted by the LGN ( a hysteretic mode of operation) 57

Feedback from hyperexcited cortical neurons will stream back to the LGN via corticogeniculate projections which outnumber geniculocortical projections ten-to-one One effect of this feedback is that the LGN is

able to absorb large amounts of information flowing back from the cortex 58

As signals reverberate back and forth in thalamocorticothalamic circuits a matching process takes place those geniculate relay cells that fire in patterns consistent with the firing patterns of active cortical cells will have their responshysivity enhanced while those geniculate cells that fire in patterns not consistent with cortical cells will be suppressed 59

Preservation of consciousness by selective facilitation of the visual pathways By combining all of the facilitatory effects produced by the authors eye movements and attentive fixation-(l) stimulation of the LGN by feedback from periorbital proprioception both directly and indirectly via the SC (2) the release of PGO waves (EMPs) that facilitate neurons in the LGN and primary visual cortex as they pass (3) the facilitation of the primary visual cortex by a state of relaxed immobile expectancy (4) attentive fixation and angle of gaze that facilitate PVNs in area PG (5) intracortical amplification of signals received from the LGN and (6) corticogeniculate feedback that stimulates the LGN-we delineate a circuit of enhanced excitability that extends from the LGN through the post-geniculate visual heirarchy to area PG where signals are integrated into representations of objects

The hyperexcitability of neurons all along the post-geniculate visual pathways creates conditions in the visual cortices which are similar to those present during EEG-desynchronized states of waking and REMS Therefore neurons in the visual pathways are too excitable to be entrained by synchronous bursting

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 140

patterns when spindle waves move through them instead the spindle bursts stimulate visual neurons to depolarize and then recover as happens in response to afferent sensory signals during waking states It is important to note that for this to occur none of the constituent neuron assemblies is required to perform an abnormal operation the abnormality is a function of the authors intent to activate contemporaneously neuron assemblies that would not normally be co-activated

PART IV HYPNOTIC ANALGESIA

Manipulation of spatial attention as a method for alleviating pain sensations In a theoretical article on the neurophysiology of hypnosis Crawford and Gruzelier60 propose that variations in hypnotizability are function of variability in the efficiency of the frontolimbic (anterior) attentional system in humans high-hypnotizables are better able to sustain focused attention on a task and to ignore extraneous stimuli than are low-hypnotizables

I na related empirical study that compares the use of attention by subjects with high versus low hypnotizability Crawford Brown and Moon61 report that highly hypnotizable persons continue to show physiological reactivity

while cognitively not perceiving the painful stimuli Through disattentional processes they can dissociate themselves from the awareness of pain The authors phosphene induction behaviors-and the cutaneous analgesia he experishyences-appear to involve the same kind of behaviors that is a mobilization of frontolimbic attention used to withdraw attention from external stimuli and to concentrate it on internally-generated phosphene images This suggests the hypothesis that the mechanisms that generate phosphenes might also produce hypnotic analgesia There are several ways that visual signals and pain signals might interact to produce this analgesia

Competition between pain and vision signals for limbic registration The fully-developed sensation of pain requires integration of rwo kinds of informashytion Signals that encode the location and intensity of a noxious stimulus (nociceptive signals) are relayed via the thalamus to the somatosensory cortices which registers only the sensory-discriminative aspects of pain perception62 before reaching consciousness the nociceptive signals must be sent to the limbic

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 141

system where they are linked with signals from long-term memory that encode the affective significance the stimulus has acquired for that individual Studies of brain metabolism show this linking of somatosensory information with limbic associations takes place in the anterior cingulate (CG) and anterior insula62-64

PET studies also show that the anterior CG is activated when subjects shift their spatial attention in response to expectations as to where

66stimuli will next appear65- This is precisely what takes place during the state of immobile expectancy that induces phosphenes Since visual signals and nociceptive signals both require limbic enhancement which is only possible if they get access to the anterior CG there might be conditions in which the two types of afferent sensory signals have to compete for that access In a theoretical article on the mechanisms of attention Posner and Rothbart67

propose that visual signals can interfere with nociceptive signals by blocking access to the anterior CG As behavioral evidence they cite studies showing that when young infants make distress calls they can be distracted by the presentation of a new visual stimulus We have shown the evidence of such control at about three months Orienting to visual events can be employed to quiet or calm negative vocalizations However the distress appears to be maintained and reappears when the infants attention to the stimulus is reduced Caregivers also report the use or visual orienting to block overt manifestations of distress at about this age 67

The effects of disattention on the somatosensory cortices If there is a competition between visual signals and nociceptive signals for access to the anterior CG it is likely that the competition will be affected by the relative volume of signals received A recent study suggests that focusing attention on internally-generated visual stimuli may reduce the number of nociceptive signals relayed by the somatosensory cortices Drevets Burton Videen Snyder Simpson and Raichle68 have shown that the mere anticipation of a touch at a specific cutaneous site increases the flow of blood to those cortical somatosenshysory neurons that are linked with that site where touch is expected and decreases the flow of blood to neurons linked with sites where touch is not expected In this experiment the researchers designated touch as the behaviorally significant sensory stimulus but their findings suggest that the outcome could be reversed if the instructions were reversed if subjects were

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page J42

instructed to direct attention away from a cutaneous site where a noxious stimulus was being applied if they were instructed to relax close their eyes and concentrate on the play of phosphenes in the visual field as the behaviorally significant sensory stimulus then it would be reasonable to expect that the flow of blood would decrease to the somatosensory neurons linked with the cutaneous stimulus and that the flow of blood would increase to the visual cortices The decrease in blood flow to somatosensory neurons implies less neuronal activity which implies that fewer signals are being sent forward to the anterior CG than would have been sent if instead the subject were treating the touch as the behaviorally significant sensory stimulus If fewer pain signals arrive at the anterior it is reasonable to infer that the conscious experience of pain will be muted by the diversion of attention to internal visual stimuli

Differential impact of sleep rhythms in the visual and nonvisual thalamus There is another mechanism that might also contribute to the analgesic effect of inducing sleep rhythms PET studies show that

the thalamus is involved in the relay of nociceptive signals to the cortex63 although some confusion remains about which kinds of signals are relayed by which subregions in the thalamus62 One thalamic site clearly identified by anatomical studies as a relay for nociceptive signals is the ventroposterior lateral nucleus (VPL)69 If synchronous sleep rhythms are active in the thalamus we can reasonably expect that the VPL will itself be entrained by synchronous oscillations and that it will relay the sleep rhythms to somatosensory cortices Relay neurons in the VPL are not stimulated by feedback from eye movements and fixation as are relay neurons in the LGN which suggests that sleep rhythms may impede the relay of nociceptive signals via the VPL but not the relay of visual signals via the LGN

Brain waves associated with anesthesia and NREMS The hypothesis presented here-that consciousness can be preserved despite the presence of NREMS activity-is consistent with a recent report that the kinds of fast brain waves which are normally associated with conscious states are also present during NREMS and anesthesia two states which were thought to involve minimal brain activityJo Another recent study found that there is a close resemblance between the slow brain waves that appear during NREMS and those that appear during certain types of anesthesia71

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 143

bull bull bull

CONCLUSION

In this paper we have presented evidence supporting the hypothesis that phosphene images can be generated as an epiphenomena of thalamic spindle bursts and delta wave activity normally associated with NREMS The prereqshyuisites for inducing these sleep rhythm phosphenes are relaxed immobile expectancy sustained convergence and attentive fixation of an undifferentiated visual field Our hypothesis provides a necessary and sufficient explanation for the authors induction of phosphenes and perhaps also for the generation of phosphenes reported to appear spontaneously during the drowsy transition to sleep (hypnagogic states) during sensory deprivation or during certain kinds of prayer or meditation all of which involve a similar state of relaxed immobile expectancyJ2

CORRESPONDENCE Philip T Nicholson bull 52 Norfolk Road bull Chestnut Hill MA 02167

REFERENCES amp NOTES

1 M 1 Posner Modulation by Instruction Nature 373 (1995) pp 198-199 2 J Reissenweber E David amp M pfotenhauer Investigations of Psychological Aspects of

the Perception of Magnetophosphenes and Electrophosphenes Biomedizinische Tecknik 373 (1992) pp 42-45

3 S M Kosslyn W L Thompson 1 J Kim amp N M Alpert Topographical Representations of Mental Images in Primary Visual Cortex Nature 378 (I995) pp 496-498

4 P E Roland amp B Gulyas Visual Memory Visual Imagery and Visual Recognition of Large Field Patterns by the Human Brain Functional Anatomy by Positron Emission Tomography Cerebral Cortex 51 (1995) pp 79-93

5 H Benson The Relaxation Response (Morrow New York NY 1975) 6 ] H Schultz amp W Luthe Autogenic Training a Physiological Approach to Psychotherapy

(Grune amp Stratton New York NY 1969) 7 E Jacobson Progressive Relaxation (University of Chicago Press Chicago IL 1938) 8 M A Steinmetz BC Motter C] DuffY amp V B Mountcastle Functional Properties

of Parietal Visual Neurons Radial Organization of Directionalities Within the Visual Field Journal ofNeuroscience 71 (1987) pp 177-191

9 R R Edelman Magnetic Resonance Imaging of the Nervous System Discussions in Neuroscience 71 Elsevier Science Amsterdam (I990) also J H Newhouse amp ] I Wiener Understanding MRI 1st Ed (Little Brown Boston MA 1991)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 144

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

I n addition to manipulating eye position the author focuses all his attention on the fixation point at the center of the visual field even though at this early stage in the phosphene induction process the visual field remains

empty of everything except random metabolic discharge referred from the retina-the eigengrau or self-generated gray light When the attention is fixated strongly enough the author experiences auditory feedback-a distincshytive tinnitis cerebri that seems part sound but also part vibration This sensation originates inside the lower rim of the skull at about the level of the ears and feels as if it radiates upward on both sides It sounds like bird wings fluttering the sputtering of an open wood fire or a dull buzz The reader can experiment with eliciting a version of this same tinnitis by staring intently at some external object located just beyond the reach of an extended arm With practice this tinnitis can be sustained for long intervals and used as a feedback signal to mark the efficiency of dissociation Long practice also conditions this response so that a slight convergence of the eyes a straight-forward stare and fixed attention are sufficient to evoke the tinnitis and then the phosphenes The author continues the stereotyped eye movements and attentive fixation until phosphenes appear and for the duration of the phosphene displays

No less important than sustained convergence and attentive fixation is the ability to keep the level of arousal low and the mental field free of distractions The author remains passive and ready to acquiesce in whatever happens To minimize the distraction of unwanted thoughts images emotions itches or pains he uses a traditional meditation strategy-not attempting to resist distracting content but rather treating its arrival with indifference letting it drift freely in and out of consciousness This disengagement from potentially disruptive thoughts combined with steady breathing and the intense focusing of attention preserves equanimity and maintains a low level of arousal

Pain control requires adding another strategy In response to a painful stimulus the large muscles of the body usually tense involuntarily and fear of further pain breaks into awareness The author counters these instinctive and involunshytary reactions by deliberately posing the thought that the pain is not actually attached to the body that the pain can be given away by allowing it to flow out of the body and to disperse in all directions in which case the author need not take action in order to escape or avoid the pain This mental strategyshyin effect a deliberate abandonment of the normal vigilance which is oriented

Subtle Energies amp EnerfJ Medicine bull Volume 7 bull Number 2 bull Page 114

toward behaviorally significant external stimuli-results in a sudden preCIpIshytous drop in tension and restoration of the former relaxed state This reshyrelaxation occurs immediately after the muscles tense involuntary in response to the painful stimuli Keeping relaxed helps diffuse the pain sensations and the anxiety about pain The anticipation that relaxation (and the relief it brings) can be quickly restored after the next painful stimulation creates confidence that events are not out of control and that therefore it is not necessary to divert ones attention from the focus on the visual field that generates the phosphenes

The authors phosphene induction method closely resembles the behaviors used as the baseline resting condition in the PET studies except that in those studies subjects were not explicitly instructed to converge their eyes or to fixate their attention However the authors attempt to carry out their instructions-lying motionless with eyes closed and having it black in front of the minds eye results in his eyes focusing automatically on the near visual field an operation which requires some convergence (although not as much as the author would normally use) His attention also focuses automatically on the center of the empty visual field If the authors experience is typical then the two sets of behaviors may be virtually the same with differences being in degree not in kind

OBSERVATIONS

PHOSPHENE RECEDING ANNULI

The threshold sequence of phosphene images is illustrated in Figure 1 Just before the appearance of phosphene there is a fleeting sensation of a movement inward from 3600 of the peripheral visual field (VF)

as if a dark annular wave were moving through the dark background with so little contrast that it is almost imperceptible This annular wave suddenly illuminates while still in the far periphery of the VF (at about 80 - 60deg of isoeccentricity) presenting a bright thin phosphene annulus yellow-green in color that decreases in diameter at a constant rate preserving its annular symmetry until it disappears into the centerpoint after 4 seconds of elapsed time (estimated by counting 1001 1002 etc) There is an interval

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 115

0- 05 sec 10 sec 15 sec

20 sec 25 sec 30 sec

Figure 1 Schematic drawings ofreceding annuli phosphenes At first there is a sensation of movement inward from 360 0 in the periphery of vision then a bright thin yellowshygreen phosphene annulus sudden~y illuminates at about 80 60 of isoeccentricity The edges ofthe annulus are well-defined but more diJfose than this computer drawing program can depict-like a wellformed smoke ring The annulus preserves its symmetry as it shrinks steadio in diameter at a constant rafe offlow creating the illusion that it is receding toward the center of vision At 2 seconds the empty space inside the annulus fills abrupto with a disk ofbrighter phosphene At 4 seconds the image disappears into the centerpoint At 5 seconds another annulus sweeps into the periphery The author sees a total of4 receding annuli

of 1 second then the next wave appears at the periphery of the VE Midway in the trajectory-at 2 seconds-the empty interior of the annulus fills abruptly with a disk of slightly brighter phosphene A sequence of annuli usually terminates after 4 images although the number of annuli can be increased by diverting the attention for a moment and then refocusing

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 116

While the color of the annulus has remained the same over time the color of the filling-in disk changed after about two years of intermittent phosphene induction from yellow-green to blue The change began with tiny flecks of blue flashing amid the green just as the disk disappeared Over a period of several weeks the amount of blue expanded and appeared earlier in the fillshysequence Within a month the entire fill-disk was blue

The shrinking annuli create a psychological illusion of a ring of light receding toward a distant point in 3-dimensional space and pulling the attention into a vortex or paradoxically the same progression can create a sensation of falling backwards an illusory motion that resembles an effect produced by optic flow Motion in the visual periphery elicits in the stationary observer an illusion of self-motion (vection) indistinguishable from real motion The illusion of vection is compelling for it dominates contradictory proprioceptive signals For example subjects presented with optic flow consistent with backward self-motion perceive backward motion even if they ate actually walking forward 8

T he same receding annuli appear spontaneously as hypnagogic images while the author is reclining and waiting for sleep The receding annuli appear whenever the authors mind and body are relaxed his eyes closed

and his attention focused straight ahead-essentially the same behaviors used for self-hypnosis-but in the hypnagogic context virtually no effort is required the receding annuli feel as if they were released spontaneously not induced If the author is not relaxed or if he is distracted by a headache or importuning thoughts then the luminous receding annuli do not appear Instead the author loses consciousness abruptly at the onset of NREMS

AMORPHOUS EXPANDING PHOSPHENES

(A) loCAL RANDOMLY-DISPERSED EXPANDING WAVES Figure 2(A) illustrates one kind of amorphous phosphene mist that appears after the receding annuli sequence terminates These phosphenes are small amorphous swirls of yellowshygreen that coalesce suddenly at unpredictable locations in the VF and expand for a second or two then fade into the background There are often several images drifting in the visual field at the same time each in a different stage of evolution and the density of the phosphene seems to vary with some areas appearing thin and translucent others more opaque-like puffs of smoke that

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 117

10 seconds 15 sec 20 sec

25 Bee 30 sec 35 sec

expand and curl aimlessly then dissipate Because these waves are so unpredictable and formless the author is unable to predict the mean number of signals per episode the period between signals the site of entry or exit or to define a typical trajectory other than in the abstract generic manner used above The signal-to-noise ratio in these phosphenes is very low since phosphene stands out against the background there clearly is a signal but this signal presents so little pattern that it is essentially a form of phosphene noise These localized pulsations may continue for several minutes but usually within a minute or two they are superceded by the type of amorphous wave described next

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 118

Figure 2 [focing page Schematic drawings of of amorphous expanding phosphenes (A) Brief randomly-dispersed localized pulses These phosphenes are the first to appear after the receding annuli They coalesce at unpredictable locations in the IF expand asymmetrically for a second or two then dissipate into eigengrau before there is time to extend very for beyond their locus of origin (B) Periodic unidirectional amorphous expanding waves These phosphene waves enter the periphery ofvision from one hemifield presenting as a loosely-defined crescent (hemi-annular) cloud that mirrors the curvature of the peripheral rim The leading edge of the wave expands and flows across the vertical meridian into the opposite hemified swirling around the periphery curling inward and merging while at the same time the trailing edge ofphosphene dissipates rapidly in those regions over which the wave has already passed like mist or smoke evaporating in air The author is unable to time these waves but their duration fiels roughly the same as for receding annuli ie about 4 seconds Waves appear one after another in a cluster with a refractory period between clusters during which no waves appear After a prolonged session ofself-hypnosis the phosphene may not completely dissipate between successive waves in which case the residual phosphene accumulates in a vaguely-circular cloud shape with a small area its center that undergoes continual perturbation the phosphene pulls back leaving a small Mrk circle at the center of the cloud then fills back in then pulls away again ebbing and flowing in like manner until the cloud dissipates At this stage the image resembles an eye with a phosphene iris and a dark inner pupil (C) Twoshytone phosphene During a prolonged session the phosphene at the very center of the amorphous cloud becomes much brighter more fine-grained almost opaque with highly saturated color When a hole (pupil) appears in the center ofthe cloud forming an eyeshyimage the brighter phosphene becomes a thin bright rim lining the Mrk hole from this bright inner rim tiny promontories ofbright phosphene flare out into the Mrk hole twist and coil and collide with other flares forming webs and momentarily filling-in the Mrk hole or receding back into the rim The two-toned phosphene does not only appear in conjunction with the eye-shape clouds it also manifests at the center ofa variety ofelusive ever-changing shapes It is always restricted to the area offoveal vision

(B) PERIODIC UNIDIRECTIONAL AMORPHOUS WAVES These phosphene waves sweep in from one hemifield as shown in Figure 2(B) Often the wave has a vaguely crescent shape at the outset that conforms to the concave curvature of the peripheral VF then the crescent shape gives way as the wave expands rapidly in divergent directions flowing smoothly across the vertical meridian to envelop those regions of the VF that have not yet been illuminated As the leading edge of the wave expands the rear edges are already beginning to dissipate The swirling movement and the contraction of outer boundaries leaves a cloud of phosphene near the center of the VE This cloud may dissipate rapidly or it may persist for several seconds during which a pertur-

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 119

bation takes place at the center of the cloud the phosphene ebbs away from this region leaving a tiny dark hole then the phosphene fills back in then it ebbs and fills again-a fluctuation that continues as long as the phosphene cloud is visible During the perturbations the phosphene vaguely resembles the iris of a human eye with an interior dark space as its pupil This eyeshyimage is seldom symmetrical and its boundaries are always changing

(c) TWO-TONE PHOSPHENE When the phosphenes are induced over a prolonged period of time the phosphene in the central region representing foveal vision presents a more intensely bright more opaque (finely-grained) character than the rest of the cloud as shown in Figure 2(C) When this brilliant opaque phosphene appears as part of an eye-image it forms a thin rim surrounding the pupiL From this rim flares jut out into the dark pupil space coil about merge or recede back into the rim

The periodic unidirectional amorphous waves do not terminate after a stereoshytyped sequence they can be evoked over prolonged rime periods if the autohypshynotic behaviors are maintained The author is unable to retain the vision of these amorphous waves while simultaneously counting the number of seconds elapsed it is his impression however that the duration of amorphous expanding waves feels about the same as for receding annuli that is a duration of about 4 seconds per wave The amorphous waves usually appear in clusters followed by a refractory interval during which no phosphenes appear even if induction behaviors are sustained

PHOSPHENES SUPERIMPOSED ON ExTERNAL OBJECTS

The author can observe amorphous phosphene images with his eyes open if he is in a room dark enough that colors cannot be distinguished or if he is

in a lighted room but one where he can keep his eyes diffusely focused on a relatively undifferentiated surface such as a wall or ceiling with a light and uniform color and no distracting decorative adornments In open-eye viewings phosphenes appear as faint translucent waves of yellow-green mist

superimposed over the surface or in the dark space that fills the darkened room If the author attempts to focus on the features of external objects the phosphenes disappear

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 120

RECEDING ANNuLI EVOKED BY MAGNETIC REsONANCE IMAGING (MRI)

A s a patient undergoing an MRI scan the author observed an unusual sequence of receding annuli He was not relaxed as in a normal induction but rather anxious about his medical condition and about

being confined in the narrow MRI tube To keep calm he concentrated on breathing slowly and stared straight ahead While the sound of MRI machine was audible the author observed a stream of receding annuli that differed from the usual sequence (self-induced and hypnagogic) in three ways (I) the MRI annuli did not terminate at 4 cycles but continued for as long as the author kept his attention focused (2) the MRI annuli were only yellowshygreen in color even though in other inductions the fill-in disk had already changed from green to blue and (3) MRI annuli completed their trajectoshyries in half the normal time disappearing in 2 seconds instead of 4 An interval of 2 seconds between radio pulses is often selected as optimal interval for capture of the signals emitted by hyperexcited atoms in the subjects body

10during the precessional relaxation 9- These observations suggest that energy released in the wake of the radio bombardment during MRI moves through the LGN as a standing wave in the same way that spindle bursts move but that the 2-second duration of the MRI wave is not long enough to activate the neurons that generate a blue sensation

THE ANESTHETIC EFFECT ASSOCIATED WITH SELF-INDUCED

PHOSPHENES

On several occasions the author has preferred to undergo minor surgery without local anesthetic and to rely instead on autohypnotic analgesia-for example during extraction of an infected abscess from the back during laser surgery to

remove keloids and during the filllng of dental caries His experience on a recent occasion when a dentist had to abrade the surface of six teeth with damaged enamel in order to create a strong bonding surface are worth describing here because the experience implies that spindle waves can be induced even during a state of high physiological arousal For this appointshyment the author arrived in the office too late to hypnotize himself in advance

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 121

so he had to begin the normal induction procedures after the dental work was already underway

A s the dentist worked on the first tooth the author experienced apprehension sharp sensations of pain and an involuntary tensing of the large muscles of the body with each application of the drill As

the author kept his eyes converged and his attention focused on the center of the visual field the involuntary tensing in response to pain alternated with a precipitous relaxing of those same muscles immediately after the stimulus With the repeated relaxation came a sense of relief and of letting go that amelioshyrated the pain The pain-driven relaxation was much stronger than the relaxation that normally accompanies the authors self-induction of phosphenes and the alternation of a pain-driven tensing on one hand and the distancing effect of focusing attention on the visual field on the other hand resulted in a rapid dissociation from all external and internal stimuli including a signifishycant amelioration of painful sensations

Most striking is the fact that by the time the dentist reached the third toothshyafter only a few minutes of this pain-driven self-hypnosis-the author saw a normal sequence of 4 receding annuli followed by swirling clouds of amorphous expanding phosphene even though the dentist was still using the drill contemporaneously This experience suggests that thalamic sleep rhythms can be voluntarily induced even when the subjects level of physiological arousal is high

SIMILARITIES WITH ATTENTION-INDUCED PHOSPHENES

REpORTED BY OTHER OBSERVERS

Taxonomies of phosphene images always include examples of simple geometric phosphenes with circular or semi-circular shapes (disks annuli or crescents) as

14well as formless phosphene mists 11 - There are also a number of anecdotal accounts that are relevant for example Friedman an opthamologist who studied entoptic images by introspection describes a similar sequence of annuli induced by sustained inward concentration Circular waves of blue color may be seen in the dark by the dark adapted retina They start at the

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 122

periphery and move inward toward the macula as a concentrically contracting solid circle disappear at the macula and begin again at the peripheryl)

A valuable but often-neglected resource of information about phosphene imagery is presented in the literature of religious mysticism Many mystics reported having seen translucent colored lights while absorbed in prayer or meditation A list of descriptions excerpted from self-reports is presented in Table 1 (These excerpts are representative of phosphene images that appear during states of calm and inward-oriented concentration they do not include images associated with paroxysmal raptures) These phosphene images exhibit a relatively limited set of shapes and colors the shapes are either circular (eg rings disks wheels suns) or formless (eg mists snow smoke) and the colors are usually a variant of either green or blue The phosphene visions of mystics display shapes and colors that are comparable to the images described by the author this and the many similarities in the behaviors used to induce phosphenes suggest that both sets of phosphenes have a common etiology

DISCUSSION

Whether the author uses self-hypnosis to induce phosphenes or experishyences them as hypnagogic images the threshold sequence of receding annuli has the same characteristics In both these

instances the antecedent behaviors involve a state of low physiological arousal combined with mental withdrawal from external stimuli These parallels suggest the hypothesis that phosphene displays are related to sleep-wake transitions

PART I RECEDING ANNULI AND THALAMIC SPINDLES

Mechanisms controlling the transition from waking to NREMS Based on the work of several research teams16-20 a consensus scenario for the generation of NREMS has emerged In this scenario NREMS is the product of three brain rhythms that interact with each other in thalamocorticothalamic circuits During the drowsy transition to sleep which in humans is called stage l NREMS the low voltage activity in the cortical electroencephalograph (EEG) still shows a pattern of intermittent desynchronization The polarization of

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 123

Table I Excerpts from self-reports of light visions by religious mystics

HEBREW MYSTICS the appearance of the wheels was like the gleaming of beryl and the four had the same form

their construction being something like a wheel within a wheel Ezekiel like a dome shining like crystal spread out about their heads And above the dome something

like a rhrone in appearance like sapphire Ezekiel a round Iodder like a full sphere rolling back and forth before him bright blue R Abulafia A glowing light clear brilliance A purple light that absorbs all lights R Moses de Leon

HINDU AND BUDDHIST MYSTICS a perfectly round beautiful deep-blue shape of a size appropriate to the center of a mandala as

if exquisitely painted of extreme c14rity Tsong Khapa a luminous revolving disc studded with lights a lotus flower in full bloom Gopi Krishna both my eyes became cemered When this happened a blue light arose in my eyes like

a candle flame without a wick and stood motionless in the ajna chakra S Muktananda

MUSLIM MYSTICS [like] chandelierssublime lights [like] stars moon or the sun Sharafuddin aI-Maneri its color is deep blue it seems to be an upsurge like water foom a spring Najmoddin Kobra visualize yourself as lying at the bottom of a well [looking up at the light of the opening] and

the well in lively downward movement Najmoddin Kobra the color green is the suprasensory uniting all the suprasensories Alaoddawleh Semnani the light rises in the Sky of the hean taking the form of light-gilling moons Najm Razi

CHRISTIAN MYSTICS his own state at prayer resembles a sapphire it is as clear and bright as the sky Evagrius descending like a bright cloud of mist like a sun round as a circle Simeon Neotheologos saw something in the air near him He did not understand the rype of thing but in some ways

it appeared to have the form of a serpent with many things that shone like eyes although they were not eyes Ignatius of Loyola

the soul puts on a green amilia [cape worn on shoulders beneath armor] John of the Cross [the almilla is like a helmet which] coverS all the senses of the head of the soul It has one

hole rhrough which the eyes may look upwards John of the Cross a round thing about rhe size of a rixdaier all bright and clear with light like a crystal H Hayen I saw a bright light and in this light the figure of a man the color of sapphireblazing with a

gentle glowing fire the three were in one light Hildegard von Bingen saw a b14zing fire incomprehensible inextinguishable with a flame in it the color of the sky

Hildegard von Bingen saw placed beneath her fuet the whole machine of the world as if it were a wheel She saw herself phced

above it her eyes of contemplation magnetized towards the incomprehensible Beatrice of Nazareth I saw the eyes I do not know if I was asleep or awake Angela of Foligno kind of sunlit winged being like a childs head beneath two little wings Abbess Thaisia laquobullbull round patterns small circles would expand and eventually dissipate only to be followed by other small

circles of light Philip St Romain an extraordinary circle of gold light pulsating against a deep violet background There were

always four or fille As soon as one would fode another would appear Philip St Romain

middotItalics added to mark words referring to (l) rings appearing in sets of four (2) amorphous shapes such as clouds or flames (3) circular or eye-like shapes (4) colors from the center of the visible spectrum (gold yellow yellow-green green bluish green) and (5) colors from the lower end of rhe visible spectrum (blue purple violet)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 124

cell membranes (Vm) has already begun to drop (hyperpolarize) in the thalamic reticular nucleus (RTN) a thin sheath of GABAnergic inhibitory neurons that acts as a pacemaker When the Vm of RTN cell membranes drops to approximately V m -60 millivolts (mV) RTN cells stop firing single spikes which are associated with waking states and instead begin firing highshyamplitude 7-14 Hertz (Hz) spike-bursts These bursts wax and wane over 1 to 3 seconds-hence the name spindle -and recur at 3 to 10 seconds Spindle volleys are relayed across the cortical mantle by thalamocortical (TC) sensory relay cells In human studies the primary criterion for onset of the first fullyshyestablished episode of NREMS or stage 2 sleep is the presence of globalized spindles in the cortical EEG

When spindle bursts from the RTN stimulate TC cells to fire in synchrony this synchronous bursting pattern overwhelms the normal capacity of TC cells to relay afferent sensory signals The loss of consciousness at the onset of stage 2 NREMS is thought to be caused by this blocking effect 21

While the RTN is firing spindle bursts through the thalamus another process is activated in the cortex large numbers of cells across the cortical mantle begin to oscillate at a very low frequency laquo 1 Hz)

The cortical slow rhythm referred back to the thalamus via corticothalamic circuits intensifies the hyperpolarizing effect of the RTN spindle bursts on TC cell membranes When V m -75 mV the TC cells begin to generate their own intrinsic calcium currents which further increases hyperpolarization At V m -90 mV the RTN neurons stop firing spindle bursts The TC cells continue to fire low-threshold calcium spikes in patterns which are controlled by the cortical slow rhythm The interaction of these two oscillations generates the delta waves (1 to 4 Hz) which are associated with stage 2 NREMS

In a study of sleep rhythms using the cortical EEG Uchida Atsumi and Kojima found that the mean number of spindles required to induce delta wave activity (that is to induce Vm = -90 mY) is 478 plusmn 162 spindles (from 3 to 7 spindles)22 The mean number of spindles in a volley remains the same for a single individual over multiple trials

Based on the consensus scenario for generation of NREMS we can predict that a phosphene image generated as an epiphenomenon of a thalamic spindle

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 125

Table II Dara show rhe degree of correspondance berween rhe pulse panerns of rhalamic spindles based on intracellular research and rhe sparioremporal panerns of receding annuli phosphenes induced by rhe author using a rechnique of self-hypnosis

Receding annuli phosphenes Thalamic spindle bursrs

Mean number of signals 4 annuli 487 (plusmn 16) bursrs

Sparial exrension vs Thin band 1 - 3 seconds durarion of signal ( 05 -15 cm)

Periodicity of signals 5 seconds 3 - 10 seconds

Simultaneity in LGNs Yes Yes

Point of entry Peripheral VF Ventral amp lareral LGN

Trajecrory Bilareral concentric Unknown

Rare of flow Cons rant rare Unknown

Signal-ro-noise rario High High (shorr bursrs) (sharp brighr discrere)

Termination of sequence Mrer 4 signals Mrer 487 (plusmn 16) signals

will present the following characteristics (1) a high-definition burst-like signal (2) that recurs within 3 to 10 seconds (3) that follows a trajectory compatible with having entered the LGN from the RTN (4) that has a predictable mean for the individual subject and a range that falls somewhere between 2 to 7 annuli and (5) that the spindles will terminate automatically

The temporal patterns of receding annuli and thalamic spindle bursts are similar Table II illustrates the close match between the timing of receding annuli phosphenes and thalamic spindle bursts The most striking similarities are the mean number of signals required to induce termination (4 annuli versus 487 spindles) and the interval between signals (5 seconds for annuli versus 3shyto-lO seconds for spindle bursts) Neither alpha theta nor beta waves present this kind of stereotyped temporal pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 126

T he spatial features of receding annuli are functions of geniculate anatomy A spindle burst moving through the LGN to the cortex will acquire certain distinctive spatiotemporal characteristics because of the

unique curvilinear and laminar anatomy of the LGN A drawing of a macaque LGN based on a clay model constructed by Le Gros Clark23 is shown in Figure 3 The primate LGN is composed of six sheets of cells or laminae that fold over a central hylus In macaques the hylus rises steeply as it extends rostrocausally forming a high arch at the posterior pole in humans the hylus is much more shallow but the functional anatomy is thought to be essentially

23 24the same in both cases - The geometry of the arch forces each lamina to bend so as to constitute in effect one-half of a conical surface and each lamina with its hemi-conical shape contains visual relay cells representing the contralatshyeral half of the visual field (VF) Operating as a pair the complementary hemishycones of the right and left LGN form the functional equivalent of a single conical surface which represents the entire VE This conical geometry of the paired LGNs means a burst of otherwise formless excitation will acquire a distinctive shape as it propagates through the laminae of the LGN Imagine a horizontal section moving along the surface of a cone from base to apex that moving section forms an annulus that shrinks in diameter as it approaches the apex but retains its annular symmetry throughout its trajectory

Figure 3 also includes drawings that show how Connolly and Van Essen24

converted the 3-dimensional structure of lamina 6 the largest and most dorsal layer into a 2-dimensional map Connolly and Van Essen used data obtained by Malpelli and Baker25 to superimpose a grid that specifies the areas in lamina 6 that contain TC cells representing various degrees of isoeccentricity in the VE We will use this map at a later point to show how the movement of a spindle wave through a pair of LGNs correlates with what appears in the VE

The location of the RTN relative to the LGN is also shown in Figure 3 The RTN spindle pacemaker is a thin sheath of GABAnergic inhibitory cells that extends along the surface of the whole posterior ventral thalamus not just the LGN This extension brings the RTN into close proximity with the portion of the LGN (lateral wing) that protrudes out from the main body of the thalamus Some of RTN wraps around and beneath the ventral edges of the LGN26 The RTN comes closest to the LGN in two areas along the ventral edges of the longest laminae (lamina 6 and 1) and along the edge of the lateral

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 127

DORSAL POLE DORSALPOIEA B

L1 L4 L3 L

DORSAL POlE DORSAL POIE (FOVEA)

G LATERAL WING

25

DORSAL POL (FOVEA)

10 _DIAL

20 WING

~

wing These areas contain TC cells that represent the far periphery of the VE If a spindle burst enters the LGN at locations where laminae are in closest proximity to the RTN-along the ventral edges-then the discharge of TC cells will begin in the most ventral portions of the laminae the regions that represent the far periphery of the VE This matches the phosphene sequence observed by the author

Our hypothesis about how this proximity between RTN and LGN affects the trajectory of spindle waves is illustrated in Figure 4 We propose that it is not possible for the author to observe a thin annulus of phosphene sweeping in from all 3600 of the peripheral VF unless spindle bursts exhibit the following

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 128

Figure 3 [facing page Drawings of primate geniculate anatomy and functional anatomy relevant to the generation ofphosphenes (A) Anterior view ofa macaque monkey LGN based on a clay model reconstruction by Le Gros Clark 23 (B) Posterior view ofthe same model showing 6 laminae folded over a central hylus to form lateral and medial wings with the hylus arching steeply upward near the posterior pole to shape the laminae into layers of hollow half-cones nested together Note that the lateral wing of the LGN is slightly larger than the medial wing so that in situ the lateral wing protrudes out from the main body of the thalamus creating a small knob visible during dissection 26 (C) Schematic drawing of an oblique section through median axis (also adapted from Le Gros Clark13 showing how the laminae fuse together at the anterior pole The afferent ganglion cell axons that form the optic tract (OT) penetrate through the anterior surface to reach their target relay cells in the laminae (D) Drawing of the most dorsal lamina-layer 6--separated from the rest of the LGN The geometric shape is a hollow half-cone so that right and left LGNs placed back-to-back form in effect a single cone Note also the position ofthe RTN shown here as a striped bar relative to lamina 6 The position of the striped bar shows that the RTN makes direct contact with lamina 6 at the edge ofthe lateral wing and also along the ventral edges (E - F) Schematic drawings adapted from Connolly and Van Essen24 that show how a 3-dimensional lamina-lamina 6--can be transformed into a 2-dimensional triangular figure lamina 6 is removed and its wings unfolded (E) creating a slightly asymmetric triangular figure (F) which is adjusted to an oblong shape (G) in order to superimshypose a grid matrix with minimal distortion The grid plots locations of TC cells that represent various isoelevations and isoazimuths in the VF locations derived from the experimental observations published by Malpeli and Baker 25 Note the relatively large amounts of laminar surface allocated to central vision (0 0

- 30 0) as compared

to peripheral vision (30 0 - 80 0)

characteristics (1) Spindle bursts must move simultaneously through both geniculate nuclei This pattern of movement is consistent with anatomical studies in primates that found axonal projections linking the right and left RTNs27-28 and with experimental studies in cats that found spindles appearing simultaneously in both right and left thalami 29 (2) Spindle waves must enter the ventral edges of the LGN first and move ventrodorsally in a highly coherent pattern-moving in effect as a standing wave This pattern of movement is consistent with in vitro experiments using sagittal slices from a ferret LGN where spindle waves originated spontaneously at the edge of a slice in an area which contains cells that represent peripheral vision then propagated toward that area of the slice containing cells that represent central vision in the ferret 3o

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 129

VF

PG BIlateral receptive lleJd of PVN YI(j Inward dmKooflality Adapled

0-- from Mortgr at at (1987)

V1

ibull t bull

RTN t t t t t t 1middot3 SECOlO BURSTS OF 7middot14 HZ SPiKES RECURRNG EVERY 3 10 SECONDS

To our knowledge the LGN is the only anatomical structure in the visual system that has the capacity of passively forcing a wave of excitation to flow across a conical surface thereby generating the sensation of a phosphene annulus that retains its symmetry as it shrinks in diameter The retina has a circular anatomy but it is not likely that the mechanical deformation of the retina would produce a wave that began simultaneously in all 3600 of the retinal rim nor that the symmetry of annular wave would be preserved as it flows inward toward the foveal region

The hypothesis presented here-that there is a structure in the visual system that imprints a conical shape on standing waves that move through it-explains

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 130

Figure 4 facing page Schematic drawing of contemporaneous events in selected regions of the visual processing hierarchy (A) The left and right RTNs fire spindle bursts simultaneously (B) The bursts pass through the right and left geniculate laminae as standing waves of depolarization entering from the ventral edges and moving ventrodorsally in parallel In order for the phosphene annulus to appear to be flowing at a constant rate the spindle wave flowing through the LCN must expand in width as it ascends ventrodorsally so that by the time the fill-in disk appears-when the center 30deg of the VF is covered by the phosphene annulus-the spindle wave must have expanded enough to activate relay cells in the most dorsal 50 of lamina 6 (C) Signals representing two complementary hemi-annuli are kept separate in the primary visual cortices (area VI) (D) Signals representing the two hemi-annuli are integrated into signals of a single annulus when they reach area PC in the posterior parietal cortex where the receptive fields of single parietal visual neurons have the capacity to register bilateral signals that exhibit opponent vector movement (that is signals converging from opposite directions along the central axes-as if an object were moving away from the viewer)46 Neurons in area PC also integrate wavelength (color) signals from the extrastriate visual pathway with signals about brightness motion and depth from the parietal visual pathway to compose a representation of an object in space-in this case of an annulus that appears to recede 32

the authors experience during MRI when he observed a continuous succession of receding annuli every 2 seconds in this view the energy of the electroshymagnetic bombardment when released during precessional relaxation flows through the geniculate laminae in the same way that the RTN spindle bursts do that is as a standing wave and thus the visual epiphenomenon is the same in both cases if the subject keeps the eyes focused straight ahead and the attention fixated In a study of phosphenes evoked by electricity in conjunction with hallucinogenic drugs Knoll Kugler Hofer and Lawder found that each subject sees specific kinds of phosphene at different frequencies and that these frequency-specific images are stable enough to be reproduced after six months31

They conclude that the tunability of the electrical stimulation frequenshycies within the EEG range to various definable phosphenes requires the existence of a resonance system One mechanism contributing to that resonance system may be the functional anatomy of the LGN

The colors of receding annuli as functions of geniculate laminar anatomy The colors of receding annuli phosphenes are consistent with the patterns of discharge spindle waves can be expected to stimulate as they move through

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 131

geniculate laminae As shown in Figure 5 the six laminae differ (1) in the types of wavelength signals relayed (2) in physical size and (3) in the area of the VF represented 24-25 Only 4 out of 6 laminae Cparvocellular layers 3shy6) contain TC cells that relay wavelength signals the other 2 laminae (magnocellular layers 1 and 2) do not encode wavelength Among parvocelshylular laminae only lamina 6 the longest and most dorsal layer contains TC cells that can represent the far periphery of the VF (from 800 to 50deg of isoeccenshytdeity) therefore when the spindle wave enters the peripheral VF only those wavelengths relayed by lamina 6 will participate in composing a cortical lightness record (See Zeki)32

I n lamina 6 ganglion cell axons arriving from the retina carry two kinds of wavelength signals (1) center-ON signals from medium-wavelength cones (M-cone center-ON) and long-wavelength cones (L-cone centershy

ON)33-35 Using the cone spectral sensitivity curves (adapted from Marks et al 36) we average the wavelengths that elicit maximal responses for M-cones (535 nanometers) and L-cones (520 nm) which yields a mean wavelength value of 550 nm In humans this wavelength generates a sensation of green or yellowshygreen the sensation observed by the author

As the spindle burst moves ventrodorsally it reaches the dorsal areas in the geniculate laminae which contain TC cells representing the central 0deg to 20deg of isoeccentrieity in the VE All 4 parvocellular laminae have TC cells which are potentially capable of representing this central region of vision but the authors observation that the color of the filling-in disk changed from green to blue implies that in the early years of phosphene induction the spindle wave must have remained close to the surface of the LGN stimulating only laminae 5 and 6 which generates a sensation of yellow-green When the fill-in disk was observed to change color from green to blue the spindle wave must have been rechanneled so that it began to penetrate below laminae 5 and 6 and to activate laminae 3 and 4 the only laminae that relay blue-sensitive signals (Sshycone center-ON signals)3 In light of the authors MRI experience it seems likely that a spindle wave requires a minimum of 2 seconds to reach the blueshysensitive cells of laminae 4 therefore during MRI when the receding annuli disappeared after 2 seconds half the normal duration the fill-disk had a green color even though it had long since change to blue in other induction settings with a 4-second trajectory

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 132

A REPRESENTATION OF THE VISUAL FIELD IN EACH LAMINA

orooqUtftc O-u OCIJ1SALfIOLI (I01flAj

0

10

20

30

40 n50 Of

60

70

20 loO 1Mgr_ II~ o UIpoundAS65 mn1MY-o actlvncL ~~~r

Jll-COMcetlImiddot~

II LAYERSU 3 GatQYancetl~ (1) ucon ceom-oyenF (2)l~cen()FF 3) ~ cenloH

II~ cng1loqctWIIIfNla

iICINe -- (t81Otdb1t1d~OH (2)~

80

B CONE SPECTRAL SENSITIVITY CURVES

S-COHS

WAVIlLllNG1llS OF UGHT IH NANOMllTERS (NM)

Figure 5 Phosphene color as a function of ganglion cell distribution in parvocellular laminae (Aj Schematic drawing ofthe proportion ofthe VF represented in each laminae The proportions shown here are based on the work of Connolly and Van Essen24 The

far periphery of vision (50 0 to 80 0 of isoeccentricity) is represented in only two laminae-laminae 1 and 6-and of these two only lamina 6 is a parvocelLular lamina capable ofencoding wavelength signals Therefore only those wavelengths relayed by lamina 6 will participate in forming a cortical lighmess record for the far periphery of the VP (B) Cone spectral sensitivity curves (adapted from Marks et al)36 Using these cone sensitivity curves we can estimate the sensation stimulated by a spindle wave moving through lamina 6 by averaging the wavelengths that elicit maximal responses for M-cones (535 nanomeshyters) and L-cones (520 nm) which yields a mean wavelength value of550 nm In humans this generates a sensation of green or yellow-green the sensation observed by the author when the receding annulus enters at the far periphery of the VP For a calculation of the cortical lightness record when a spindle wave moves through 20deg to 0deg ofthe VF stimulating all 4 parvocelfular laminae see the text and Figure 6

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 133

Once the spindle wave penetrates to laminae 3 and 4 it may activate all 4 parvocellular laminae stimulating TC cells to send contradictory wavelength signals for the same retinotopic location the signals sent from laminae 4 and 3 will encode blue light (S-cone center-ON plus M-cone center-OFF and Lshycone center-OFF) while the signals sent from laminae 5 and 6 encode yellowshygreen light (M-cone center-ON plus L-cone center-ON) This kind of contrashydiction does not occur in normal retina-based perception where light energy striking the retina is structured by the retinas center-surround and colorshyopponent organization to encode only one set of wavelength signals for each spatial locus 32 In Figure 6 we estimate the cortical lightness record that results when contradictory wavelength signals compete to be represented in consciousshyness Our calculations suggest that the outcome will be a mean wavelength which in humans elicits a dark blue or violet sensation

PART II AMORPHOUS PHOSPHENES amp THALAMIC DELTA ACTMTY

M echanisms controlling the transition from spindle bursts to delta activity In the consensus scenario for the generation of NREMS16-20 we noted that the RTN shifts to firing spindle bursts

when polarization of thalamic cell membranes drops to V m = - 60 mV At the same time cortical cells begin oscillating with a synchronous slow rhythm laquo 1 Hz) Both processes further decrease the Vm of TC cell membranes When Vm = - 75 mY TC cells begin to generate their own intrinsic calcium currents which also decreases V m At V m = - 90 mV RTN neurons stop firing spindle bursts At the same time the TC cells begin firing low-threshold calcium spikes in alternation with after-hyperpolarizations (LTS-AHP) Because sensory relay neurons in the LGN are not linked to one another by locally projecting axons the firing of one TC cell does not excite its neighbor However a lack of local connectivity does not mean that TC cells occupying the same laminae release their AHP-LTS calcium spikes in a random distribshyution rather spikes are released simultaneously by groups of cells in synchrony with the advent of the cortical slow wave In effect the distribution of LTSshyAHP spikes firing in the LGN is determined by the spatial propagation of the cortical slow wave Thus the delta wave (1 to 4 Hz) activity detected by cortical EEG during NREMS is a product of the interaction between the AHP-LTS calcium spikes released by TC cells and the cortical slow rhythm

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 134

CORTICAL PROCESSING OF CONTRADICTORY

WAVELENGTH SIGNALS

KEY _ Cells firing

cJ Cononol firing

Assume that as a spind6e wave moves through the LGNlt fires simultaneously aU the TC cells that represent a particular reUnoshytopic locus (x y) in each of the six laminae As a result cortical cells engaged In the higher level processing of visual signals will receive more wavelength signals representing retina locus (x y) than are generated by normal perception laquo and some of these afferent wavelength signals may contradict other signals arriving simultaneously

CORTICAL LIGHTNESS RECORD SlgnalSell

Intemal contradictions not congruent wilt pre

SmiddotON eristing neuron neta

s bullbull M-ON LmiddotON

3 bullbull M-OFF + L-OFF

a-ON 12

ROD-ON

No Internal eonlradlemiddot

--------1I =~8b~~~~~~~t signals

3+4

~ --OFF Excludes 6 Of 7 $J9n18

1+2 B-ON I

IWmiddotHmiddotI Signal Sell

1111111 No Intern1 conlrfldlcshy lion

Exelvdta 4 out of 7 efshy

bullbullbull bullbullbull ferant signals

No Intern1 contradic_ tionnee S-ON BshyOH and ROO-ON can all be coacllve at low lImlnance levels nef Ihe rod-eone break

ExchJde$ only 2 Ollt of 7 afferent signals

Figure 6 Selection of competing wavelength signals based on neuronal group selection This thought experiment is based on Edelman sconcept ofneuronal group selection 73 We assume that all possible combinations ofsignals will form sets and that all signal-sets will compete to make the most efficient match with pre-existing neuromd networks that have been forged over years ofnorma reti1U1-based perception We also assume that pre-existing neural networks are most likely to expedite those sets that satisfY 2 criteriI (J) the signals in a set do not contradict each other and (2) fower signals are excluded than in the other sets that satisfY the first criterion In our analysis Set 4 wins the competition because it does not contain internal contradictions and excludes fower signals (2 out of 7) than Set 3 excludes (4 out of7) It is not an internal contradiction that Set 4 contains both rods and cone Signtlls in normal retina-based perception when luminance levels approach the rod-cone break S-cone center-ON receptors send signas as do rod receptors and there is even evidence that rod activity may actually drive S-cone activity even after luminance levels foIl below the rod-cone break74 To calculate the cortical lightness record for Set 4 we average the wavelength that elicits maximal responses foom rods (511 nm) and for Sshycones (430 nm) which yields a mean wavelength of 470 nm which in humans results in a dark-blue or violet sensation

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 135

The cortical slow rhythm is an example of a generic pattern of neuronal excitashytion that occurs in large networks of neurons linked by local projections A recent experiment by Maeda Robinson and Kwana38 shows that networks of locally-connected neurons spontaneously generate periodic synchronized bursts of calcium transients that propagate across the network in an expanding spatial wave a pattern that represents a stable mode of firing towards which these neuronal networks relax following perturbations for example by electronic stimulation or by drugs Understanding the characteristics of these waves is an important prerequisite to understanding the mechanisms that produce the amorphous phosphene images as a visual epiphenomenon

To study the spontaneous periodic synchronized bursts the researchers prepared cultures of dissociated cortical neurons and allowed them to mature for several days in vitro (DIV) After 3 to 4 DIV when concenshy

trations of extracellular magnesium were low electrodes began to detect spontaneous synchronized bursts of low frequency calcium transients (between 01 and 1 Hz) that originated in different locations on the sheet every 10 to 20 seconds and spread across the sheet of cells at a relatively slow speed averaging 50 mmsecond The researchers could not predict where a wave would originate or where it would expand rather the initiation and expansion of waves was generated by spatial and temporal summation of a continuous random background of synaptic inputs including miniature spontaneous synaptic events but the pattern was not random since waves propagated sequentially from electrode to electrode as each local group of neurons charges up its neighboring nontefractory areas rather than in a random sequence of regions38

The excitability of the cells in the sheet determines the probability first that there will be a synchronous burst and second that it will spread in a particshyular direction Cells become more excitable as the cultures mature which means the refractory intervals between successive bursts were much shorter in mature cultures (gt 30 DIV) than in early cultures laquo 7 DIV) Some cells became so insensitive to inhibition that they continued to fire bursts even when extracellular concentrations of magnesium were relatively high Finally there were refractory periods of 5 to 10 seconds during which no bursts occurred even when an electrical stimulus was applied This refractory interval for cultured networks is slightly longer than the refractory interval observed of the cortical slow wave in vivo which 25 to 4 seconds 18- 19

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 136

Based on the observations about cortical slow waves we can predict that phosphenes generated as epiphenomena of delta wave activity will present the following signal characteristics (1) signals that appear at unpredictable locations in the VF (2) signals that expand and diverge asymmetrically following unpredictable trajectories which may encompass large areas of the VF (3) signals that move relatively slowly (50 mmsec) (4) signals that recur with a period of 2 to 4 seconds reflecting entrainment by the cortical slow wave (5) signals that do not terminate automatically after a predictable number of cycles

The spatial patterns of phosphene mists and thalamic delta waves are similar The spatiotemporal characteristics of amorphous phosphenes match the pattern of wave propagation associated with periodic spontashy

neous synchronized bursts in large neuron networks the amorphous phosphenes enter the visual field at unpredictable locations expand and diverge asymmetrically with a slow steady rate of flow follow trajectories that are unpredictable and exhibit a refractory interval The amorphous mists do appear to have a periodicity although the author is unable to sustain the vision while also counting the seconds therefore he is unable to determine if it compares to the period of the cortical slow wave (25 to 4 seconds) but his impression is that it feels roughly the same as as with receding annuli which recur at 5 seconds Also the refractory interval feels as if it decreases as the induction session is extended These similarities suggest that the amorphous phosphenes are generated by stage 2 NREMS delta wave activity which is an activity governed by the reverberation of the cortical slow wave in thalamoshycorticothalamic circuits The cortical slow wave is referred to the LGN where it modulates the firing of visual relay cells in the laminae and since relay cells do not have local dendritic connections the expansion of a wave of depolarshyizations moving from one relay cell to the next across in the laminar surface will mirror at least in part the expansion of the cortical wave that is spreading contemporaneously through locally-connected cortical cells

PART III RETENTION OF CONSCIOUSNESS

In a normal transition to NREMS the volley of synchronous spindle bursts that marks the onset of stage 2 NREMS overwhelms the normal firing pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 137

of thalamocortical cells preventing their relay of afferent sensory signals and inducing a loss of consciousness21 But the loss of consciousness cannot be timed precisely using cortical EEG the thalamus is too remote for the onset of spindling to be reliably detected by scalp electrodes39 In experiments with cats where electrodes could be implanted in the thalamus researchers found that spindling often reached peak levels of activity in the thalamus-a level of activity consonant with stage 2 NREMS-at a time when the cortical EEG was still showing intermittent desynchronizations a pattern characteristic of the drowsy stage 1 transition not a fully-established stage 2 NREMS episode4o

In other words there is a short period of time in which the synchronous rhythms of stage 2 NREMS are installed in the thalamus but not in the cortex where cortical neurons continue to depolarize in response to afferent sensory signals

T his finding suggests a possible explanation for the authors ability to retain consciousness while spindle bursts are sweeping through the LGN if he is able to extend the duration of this time lag between

the onset of spindling in the thalamus and spindling in the cortex if he is able to stimulate the visual cortices in such a way that they continue to depolarize then he may be able to keep on processing visual signals-to remain visually aware-even after the non-visual thalamus and non-visual cortex become entrained by synchronous sleep rhythms The authors induction technique includes several behaviors which are known to enhance the responsiveness of visual neurons-eye movements attentive fixation and an attitude of expectancy

Effects of eye movements and attention on the LGN Sustained convergence causes periorbital proprioceptors to send excitatory feedback directly to the LGN41 Also convergence further enhances the excitability of geniculate cells by stimulating the superior collicus (SC) which sends its own excitatory signals to the LGN42-43 These signals from the SC are known to selectively enhance the excitability of visual relay cells that represent the periphery of vision44 We know in the authors case that the SC is being stimulated because he is able to keep on fixating an ability which would normally be lost during the transishytion to NREMS45 The ability to fixate can be retained however if the SC is stimulated (even if stimulated during NREMS)46

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 138

Effects of eye movement attention and expectancy on the primary visual cortex The PET study of mental imagery by Kosslyn et al 3 showed that even a baseline resting state of relaxed immobile expectancy can generate signifishycant increases in neuronal activity in the primary visual cortices Further increases can be induced by sustained eye movements

A sustained convergence will release a stream of ponto-geniculo-occipital (PGO) waves These PGO waves called eye movement potentials or EMPs last only as long as the eye movement1747 whereas the PGO waves associated with rapid-eye-movement sleep (REMS) fire continually for the duration of the REMS episode Both REMS-related PGO waves and EMPs have the same desynchronizing effect on the visual pathways they move through the LGN depolarizing the thalamocortical cells which relay the signals to cortical neurons The responsivity of neurons in the primary visual cortices is enhanced by the stimulation of PGO waves 1747-49 If the passage of EMPs causes the genicushylate relay cells and their cortical targets to depolarize regularly then a volley of 4 spindle bursts moving through the same pathways will register as just another series of depolarizations in effect the spindle bursts are processed by the visual system as if they were sensory signals sent from the retina rather than an event stimulated by endogenous mechanisms

T he impact of eye movements and ftxation on the parietal visual cortex Convergence and attentive fixation will also enhance the responsiveness of light-sensitive parietal visual neurons (PVNs) in area PG of the

posterior parietal cortex 50 In experiments where monkeys are trained to fix their attention on a screen-and to keep on fixating even if no targets appearshythe excitability of these light-sensitive PVNs increases by as much as 350 51

52-53Responsiveness is also facilitated by the angle of gaze Also area PG is the first region in the visual pathways containing individual neurons with the capacity to respond to large bilateral stimuli moving in opposite directions along the central meridians of vision (opponent vector motion) 853-55 Facilitation of PVNs in area PG has the effect of sensitizing the subject to bilateral opponent vector motion and this is especially true if the movement appears in the periphery of the VE 8

Intracortical ampliftcation and feedback to the LGN When PGO waves and signals from the SC arrive in the primary visual cortex they may be relatively weak however weak signals can be amplified by reverberating in large networks

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 139

of cortical cells linked by local projection 56 There are nine times as many excitatory links among cortical cells as there are projections from the visual cortex to the LGN an imbalance which suggests leads Suarez Koch and Douglas to propose that geniculate input provides only a minor fraction of the excitatory input the majority originating in neighboring and recurrently connected cortical cells57 If the excitabiliry of cortical neurons is slightly higher than normal then this process of amplification may continue even after the LGN signals that initiated the reverberation are no longer being transmitted by the LGN ( a hysteretic mode of operation) 57

Feedback from hyperexcited cortical neurons will stream back to the LGN via corticogeniculate projections which outnumber geniculocortical projections ten-to-one One effect of this feedback is that the LGN is

able to absorb large amounts of information flowing back from the cortex 58

As signals reverberate back and forth in thalamocorticothalamic circuits a matching process takes place those geniculate relay cells that fire in patterns consistent with the firing patterns of active cortical cells will have their responshysivity enhanced while those geniculate cells that fire in patterns not consistent with cortical cells will be suppressed 59

Preservation of consciousness by selective facilitation of the visual pathways By combining all of the facilitatory effects produced by the authors eye movements and attentive fixation-(l) stimulation of the LGN by feedback from periorbital proprioception both directly and indirectly via the SC (2) the release of PGO waves (EMPs) that facilitate neurons in the LGN and primary visual cortex as they pass (3) the facilitation of the primary visual cortex by a state of relaxed immobile expectancy (4) attentive fixation and angle of gaze that facilitate PVNs in area PG (5) intracortical amplification of signals received from the LGN and (6) corticogeniculate feedback that stimulates the LGN-we delineate a circuit of enhanced excitability that extends from the LGN through the post-geniculate visual heirarchy to area PG where signals are integrated into representations of objects

The hyperexcitability of neurons all along the post-geniculate visual pathways creates conditions in the visual cortices which are similar to those present during EEG-desynchronized states of waking and REMS Therefore neurons in the visual pathways are too excitable to be entrained by synchronous bursting

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 140

patterns when spindle waves move through them instead the spindle bursts stimulate visual neurons to depolarize and then recover as happens in response to afferent sensory signals during waking states It is important to note that for this to occur none of the constituent neuron assemblies is required to perform an abnormal operation the abnormality is a function of the authors intent to activate contemporaneously neuron assemblies that would not normally be co-activated

PART IV HYPNOTIC ANALGESIA

Manipulation of spatial attention as a method for alleviating pain sensations In a theoretical article on the neurophysiology of hypnosis Crawford and Gruzelier60 propose that variations in hypnotizability are function of variability in the efficiency of the frontolimbic (anterior) attentional system in humans high-hypnotizables are better able to sustain focused attention on a task and to ignore extraneous stimuli than are low-hypnotizables

I na related empirical study that compares the use of attention by subjects with high versus low hypnotizability Crawford Brown and Moon61 report that highly hypnotizable persons continue to show physiological reactivity

while cognitively not perceiving the painful stimuli Through disattentional processes they can dissociate themselves from the awareness of pain The authors phosphene induction behaviors-and the cutaneous analgesia he experishyences-appear to involve the same kind of behaviors that is a mobilization of frontolimbic attention used to withdraw attention from external stimuli and to concentrate it on internally-generated phosphene images This suggests the hypothesis that the mechanisms that generate phosphenes might also produce hypnotic analgesia There are several ways that visual signals and pain signals might interact to produce this analgesia

Competition between pain and vision signals for limbic registration The fully-developed sensation of pain requires integration of rwo kinds of informashytion Signals that encode the location and intensity of a noxious stimulus (nociceptive signals) are relayed via the thalamus to the somatosensory cortices which registers only the sensory-discriminative aspects of pain perception62 before reaching consciousness the nociceptive signals must be sent to the limbic

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 141

system where they are linked with signals from long-term memory that encode the affective significance the stimulus has acquired for that individual Studies of brain metabolism show this linking of somatosensory information with limbic associations takes place in the anterior cingulate (CG) and anterior insula62-64

PET studies also show that the anterior CG is activated when subjects shift their spatial attention in response to expectations as to where

66stimuli will next appear65- This is precisely what takes place during the state of immobile expectancy that induces phosphenes Since visual signals and nociceptive signals both require limbic enhancement which is only possible if they get access to the anterior CG there might be conditions in which the two types of afferent sensory signals have to compete for that access In a theoretical article on the mechanisms of attention Posner and Rothbart67

propose that visual signals can interfere with nociceptive signals by blocking access to the anterior CG As behavioral evidence they cite studies showing that when young infants make distress calls they can be distracted by the presentation of a new visual stimulus We have shown the evidence of such control at about three months Orienting to visual events can be employed to quiet or calm negative vocalizations However the distress appears to be maintained and reappears when the infants attention to the stimulus is reduced Caregivers also report the use or visual orienting to block overt manifestations of distress at about this age 67

The effects of disattention on the somatosensory cortices If there is a competition between visual signals and nociceptive signals for access to the anterior CG it is likely that the competition will be affected by the relative volume of signals received A recent study suggests that focusing attention on internally-generated visual stimuli may reduce the number of nociceptive signals relayed by the somatosensory cortices Drevets Burton Videen Snyder Simpson and Raichle68 have shown that the mere anticipation of a touch at a specific cutaneous site increases the flow of blood to those cortical somatosenshysory neurons that are linked with that site where touch is expected and decreases the flow of blood to neurons linked with sites where touch is not expected In this experiment the researchers designated touch as the behaviorally significant sensory stimulus but their findings suggest that the outcome could be reversed if the instructions were reversed if subjects were

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page J42

instructed to direct attention away from a cutaneous site where a noxious stimulus was being applied if they were instructed to relax close their eyes and concentrate on the play of phosphenes in the visual field as the behaviorally significant sensory stimulus then it would be reasonable to expect that the flow of blood would decrease to the somatosensory neurons linked with the cutaneous stimulus and that the flow of blood would increase to the visual cortices The decrease in blood flow to somatosensory neurons implies less neuronal activity which implies that fewer signals are being sent forward to the anterior CG than would have been sent if instead the subject were treating the touch as the behaviorally significant sensory stimulus If fewer pain signals arrive at the anterior it is reasonable to infer that the conscious experience of pain will be muted by the diversion of attention to internal visual stimuli

Differential impact of sleep rhythms in the visual and nonvisual thalamus There is another mechanism that might also contribute to the analgesic effect of inducing sleep rhythms PET studies show that

the thalamus is involved in the relay of nociceptive signals to the cortex63 although some confusion remains about which kinds of signals are relayed by which subregions in the thalamus62 One thalamic site clearly identified by anatomical studies as a relay for nociceptive signals is the ventroposterior lateral nucleus (VPL)69 If synchronous sleep rhythms are active in the thalamus we can reasonably expect that the VPL will itself be entrained by synchronous oscillations and that it will relay the sleep rhythms to somatosensory cortices Relay neurons in the VPL are not stimulated by feedback from eye movements and fixation as are relay neurons in the LGN which suggests that sleep rhythms may impede the relay of nociceptive signals via the VPL but not the relay of visual signals via the LGN

Brain waves associated with anesthesia and NREMS The hypothesis presented here-that consciousness can be preserved despite the presence of NREMS activity-is consistent with a recent report that the kinds of fast brain waves which are normally associated with conscious states are also present during NREMS and anesthesia two states which were thought to involve minimal brain activityJo Another recent study found that there is a close resemblance between the slow brain waves that appear during NREMS and those that appear during certain types of anesthesia71

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 143

bull bull bull

CONCLUSION

In this paper we have presented evidence supporting the hypothesis that phosphene images can be generated as an epiphenomena of thalamic spindle bursts and delta wave activity normally associated with NREMS The prereqshyuisites for inducing these sleep rhythm phosphenes are relaxed immobile expectancy sustained convergence and attentive fixation of an undifferentiated visual field Our hypothesis provides a necessary and sufficient explanation for the authors induction of phosphenes and perhaps also for the generation of phosphenes reported to appear spontaneously during the drowsy transition to sleep (hypnagogic states) during sensory deprivation or during certain kinds of prayer or meditation all of which involve a similar state of relaxed immobile expectancyJ2

CORRESPONDENCE Philip T Nicholson bull 52 Norfolk Road bull Chestnut Hill MA 02167

REFERENCES amp NOTES

1 M 1 Posner Modulation by Instruction Nature 373 (1995) pp 198-199 2 J Reissenweber E David amp M pfotenhauer Investigations of Psychological Aspects of

the Perception of Magnetophosphenes and Electrophosphenes Biomedizinische Tecknik 373 (1992) pp 42-45

3 S M Kosslyn W L Thompson 1 J Kim amp N M Alpert Topographical Representations of Mental Images in Primary Visual Cortex Nature 378 (I995) pp 496-498

4 P E Roland amp B Gulyas Visual Memory Visual Imagery and Visual Recognition of Large Field Patterns by the Human Brain Functional Anatomy by Positron Emission Tomography Cerebral Cortex 51 (1995) pp 79-93

5 H Benson The Relaxation Response (Morrow New York NY 1975) 6 ] H Schultz amp W Luthe Autogenic Training a Physiological Approach to Psychotherapy

(Grune amp Stratton New York NY 1969) 7 E Jacobson Progressive Relaxation (University of Chicago Press Chicago IL 1938) 8 M A Steinmetz BC Motter C] DuffY amp V B Mountcastle Functional Properties

of Parietal Visual Neurons Radial Organization of Directionalities Within the Visual Field Journal ofNeuroscience 71 (1987) pp 177-191

9 R R Edelman Magnetic Resonance Imaging of the Nervous System Discussions in Neuroscience 71 Elsevier Science Amsterdam (I990) also J H Newhouse amp ] I Wiener Understanding MRI 1st Ed (Little Brown Boston MA 1991)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 144

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

toward behaviorally significant external stimuli-results in a sudden preCIpIshytous drop in tension and restoration of the former relaxed state This reshyrelaxation occurs immediately after the muscles tense involuntary in response to the painful stimuli Keeping relaxed helps diffuse the pain sensations and the anxiety about pain The anticipation that relaxation (and the relief it brings) can be quickly restored after the next painful stimulation creates confidence that events are not out of control and that therefore it is not necessary to divert ones attention from the focus on the visual field that generates the phosphenes

The authors phosphene induction method closely resembles the behaviors used as the baseline resting condition in the PET studies except that in those studies subjects were not explicitly instructed to converge their eyes or to fixate their attention However the authors attempt to carry out their instructions-lying motionless with eyes closed and having it black in front of the minds eye results in his eyes focusing automatically on the near visual field an operation which requires some convergence (although not as much as the author would normally use) His attention also focuses automatically on the center of the empty visual field If the authors experience is typical then the two sets of behaviors may be virtually the same with differences being in degree not in kind

OBSERVATIONS

PHOSPHENE RECEDING ANNULI

The threshold sequence of phosphene images is illustrated in Figure 1 Just before the appearance of phosphene there is a fleeting sensation of a movement inward from 3600 of the peripheral visual field (VF)

as if a dark annular wave were moving through the dark background with so little contrast that it is almost imperceptible This annular wave suddenly illuminates while still in the far periphery of the VF (at about 80 - 60deg of isoeccentricity) presenting a bright thin phosphene annulus yellow-green in color that decreases in diameter at a constant rate preserving its annular symmetry until it disappears into the centerpoint after 4 seconds of elapsed time (estimated by counting 1001 1002 etc) There is an interval

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 115

0- 05 sec 10 sec 15 sec

20 sec 25 sec 30 sec

Figure 1 Schematic drawings ofreceding annuli phosphenes At first there is a sensation of movement inward from 360 0 in the periphery of vision then a bright thin yellowshygreen phosphene annulus sudden~y illuminates at about 80 60 of isoeccentricity The edges ofthe annulus are well-defined but more diJfose than this computer drawing program can depict-like a wellformed smoke ring The annulus preserves its symmetry as it shrinks steadio in diameter at a constant rafe offlow creating the illusion that it is receding toward the center of vision At 2 seconds the empty space inside the annulus fills abrupto with a disk ofbrighter phosphene At 4 seconds the image disappears into the centerpoint At 5 seconds another annulus sweeps into the periphery The author sees a total of4 receding annuli

of 1 second then the next wave appears at the periphery of the VE Midway in the trajectory-at 2 seconds-the empty interior of the annulus fills abruptly with a disk of slightly brighter phosphene A sequence of annuli usually terminates after 4 images although the number of annuli can be increased by diverting the attention for a moment and then refocusing

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 116

While the color of the annulus has remained the same over time the color of the filling-in disk changed after about two years of intermittent phosphene induction from yellow-green to blue The change began with tiny flecks of blue flashing amid the green just as the disk disappeared Over a period of several weeks the amount of blue expanded and appeared earlier in the fillshysequence Within a month the entire fill-disk was blue

The shrinking annuli create a psychological illusion of a ring of light receding toward a distant point in 3-dimensional space and pulling the attention into a vortex or paradoxically the same progression can create a sensation of falling backwards an illusory motion that resembles an effect produced by optic flow Motion in the visual periphery elicits in the stationary observer an illusion of self-motion (vection) indistinguishable from real motion The illusion of vection is compelling for it dominates contradictory proprioceptive signals For example subjects presented with optic flow consistent with backward self-motion perceive backward motion even if they ate actually walking forward 8

T he same receding annuli appear spontaneously as hypnagogic images while the author is reclining and waiting for sleep The receding annuli appear whenever the authors mind and body are relaxed his eyes closed

and his attention focused straight ahead-essentially the same behaviors used for self-hypnosis-but in the hypnagogic context virtually no effort is required the receding annuli feel as if they were released spontaneously not induced If the author is not relaxed or if he is distracted by a headache or importuning thoughts then the luminous receding annuli do not appear Instead the author loses consciousness abruptly at the onset of NREMS

AMORPHOUS EXPANDING PHOSPHENES

(A) loCAL RANDOMLY-DISPERSED EXPANDING WAVES Figure 2(A) illustrates one kind of amorphous phosphene mist that appears after the receding annuli sequence terminates These phosphenes are small amorphous swirls of yellowshygreen that coalesce suddenly at unpredictable locations in the VF and expand for a second or two then fade into the background There are often several images drifting in the visual field at the same time each in a different stage of evolution and the density of the phosphene seems to vary with some areas appearing thin and translucent others more opaque-like puffs of smoke that

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 117

10 seconds 15 sec 20 sec

25 Bee 30 sec 35 sec

expand and curl aimlessly then dissipate Because these waves are so unpredictable and formless the author is unable to predict the mean number of signals per episode the period between signals the site of entry or exit or to define a typical trajectory other than in the abstract generic manner used above The signal-to-noise ratio in these phosphenes is very low since phosphene stands out against the background there clearly is a signal but this signal presents so little pattern that it is essentially a form of phosphene noise These localized pulsations may continue for several minutes but usually within a minute or two they are superceded by the type of amorphous wave described next

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 118

Figure 2 [focing page Schematic drawings of of amorphous expanding phosphenes (A) Brief randomly-dispersed localized pulses These phosphenes are the first to appear after the receding annuli They coalesce at unpredictable locations in the IF expand asymmetrically for a second or two then dissipate into eigengrau before there is time to extend very for beyond their locus of origin (B) Periodic unidirectional amorphous expanding waves These phosphene waves enter the periphery ofvision from one hemifield presenting as a loosely-defined crescent (hemi-annular) cloud that mirrors the curvature of the peripheral rim The leading edge of the wave expands and flows across the vertical meridian into the opposite hemified swirling around the periphery curling inward and merging while at the same time the trailing edge ofphosphene dissipates rapidly in those regions over which the wave has already passed like mist or smoke evaporating in air The author is unable to time these waves but their duration fiels roughly the same as for receding annuli ie about 4 seconds Waves appear one after another in a cluster with a refractory period between clusters during which no waves appear After a prolonged session ofself-hypnosis the phosphene may not completely dissipate between successive waves in which case the residual phosphene accumulates in a vaguely-circular cloud shape with a small area its center that undergoes continual perturbation the phosphene pulls back leaving a small Mrk circle at the center of the cloud then fills back in then pulls away again ebbing and flowing in like manner until the cloud dissipates At this stage the image resembles an eye with a phosphene iris and a dark inner pupil (C) Twoshytone phosphene During a prolonged session the phosphene at the very center of the amorphous cloud becomes much brighter more fine-grained almost opaque with highly saturated color When a hole (pupil) appears in the center ofthe cloud forming an eyeshyimage the brighter phosphene becomes a thin bright rim lining the Mrk hole from this bright inner rim tiny promontories ofbright phosphene flare out into the Mrk hole twist and coil and collide with other flares forming webs and momentarily filling-in the Mrk hole or receding back into the rim The two-toned phosphene does not only appear in conjunction with the eye-shape clouds it also manifests at the center ofa variety ofelusive ever-changing shapes It is always restricted to the area offoveal vision

(B) PERIODIC UNIDIRECTIONAL AMORPHOUS WAVES These phosphene waves sweep in from one hemifield as shown in Figure 2(B) Often the wave has a vaguely crescent shape at the outset that conforms to the concave curvature of the peripheral VF then the crescent shape gives way as the wave expands rapidly in divergent directions flowing smoothly across the vertical meridian to envelop those regions of the VF that have not yet been illuminated As the leading edge of the wave expands the rear edges are already beginning to dissipate The swirling movement and the contraction of outer boundaries leaves a cloud of phosphene near the center of the VE This cloud may dissipate rapidly or it may persist for several seconds during which a pertur-

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 119

bation takes place at the center of the cloud the phosphene ebbs away from this region leaving a tiny dark hole then the phosphene fills back in then it ebbs and fills again-a fluctuation that continues as long as the phosphene cloud is visible During the perturbations the phosphene vaguely resembles the iris of a human eye with an interior dark space as its pupil This eyeshyimage is seldom symmetrical and its boundaries are always changing

(c) TWO-TONE PHOSPHENE When the phosphenes are induced over a prolonged period of time the phosphene in the central region representing foveal vision presents a more intensely bright more opaque (finely-grained) character than the rest of the cloud as shown in Figure 2(C) When this brilliant opaque phosphene appears as part of an eye-image it forms a thin rim surrounding the pupiL From this rim flares jut out into the dark pupil space coil about merge or recede back into the rim

The periodic unidirectional amorphous waves do not terminate after a stereoshytyped sequence they can be evoked over prolonged rime periods if the autohypshynotic behaviors are maintained The author is unable to retain the vision of these amorphous waves while simultaneously counting the number of seconds elapsed it is his impression however that the duration of amorphous expanding waves feels about the same as for receding annuli that is a duration of about 4 seconds per wave The amorphous waves usually appear in clusters followed by a refractory interval during which no phosphenes appear even if induction behaviors are sustained

PHOSPHENES SUPERIMPOSED ON ExTERNAL OBJECTS

The author can observe amorphous phosphene images with his eyes open if he is in a room dark enough that colors cannot be distinguished or if he is

in a lighted room but one where he can keep his eyes diffusely focused on a relatively undifferentiated surface such as a wall or ceiling with a light and uniform color and no distracting decorative adornments In open-eye viewings phosphenes appear as faint translucent waves of yellow-green mist

superimposed over the surface or in the dark space that fills the darkened room If the author attempts to focus on the features of external objects the phosphenes disappear

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 120

RECEDING ANNuLI EVOKED BY MAGNETIC REsONANCE IMAGING (MRI)

A s a patient undergoing an MRI scan the author observed an unusual sequence of receding annuli He was not relaxed as in a normal induction but rather anxious about his medical condition and about

being confined in the narrow MRI tube To keep calm he concentrated on breathing slowly and stared straight ahead While the sound of MRI machine was audible the author observed a stream of receding annuli that differed from the usual sequence (self-induced and hypnagogic) in three ways (I) the MRI annuli did not terminate at 4 cycles but continued for as long as the author kept his attention focused (2) the MRI annuli were only yellowshygreen in color even though in other inductions the fill-in disk had already changed from green to blue and (3) MRI annuli completed their trajectoshyries in half the normal time disappearing in 2 seconds instead of 4 An interval of 2 seconds between radio pulses is often selected as optimal interval for capture of the signals emitted by hyperexcited atoms in the subjects body

10during the precessional relaxation 9- These observations suggest that energy released in the wake of the radio bombardment during MRI moves through the LGN as a standing wave in the same way that spindle bursts move but that the 2-second duration of the MRI wave is not long enough to activate the neurons that generate a blue sensation

THE ANESTHETIC EFFECT ASSOCIATED WITH SELF-INDUCED

PHOSPHENES

On several occasions the author has preferred to undergo minor surgery without local anesthetic and to rely instead on autohypnotic analgesia-for example during extraction of an infected abscess from the back during laser surgery to

remove keloids and during the filllng of dental caries His experience on a recent occasion when a dentist had to abrade the surface of six teeth with damaged enamel in order to create a strong bonding surface are worth describing here because the experience implies that spindle waves can be induced even during a state of high physiological arousal For this appointshyment the author arrived in the office too late to hypnotize himself in advance

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 121

so he had to begin the normal induction procedures after the dental work was already underway

A s the dentist worked on the first tooth the author experienced apprehension sharp sensations of pain and an involuntary tensing of the large muscles of the body with each application of the drill As

the author kept his eyes converged and his attention focused on the center of the visual field the involuntary tensing in response to pain alternated with a precipitous relaxing of those same muscles immediately after the stimulus With the repeated relaxation came a sense of relief and of letting go that amelioshyrated the pain The pain-driven relaxation was much stronger than the relaxation that normally accompanies the authors self-induction of phosphenes and the alternation of a pain-driven tensing on one hand and the distancing effect of focusing attention on the visual field on the other hand resulted in a rapid dissociation from all external and internal stimuli including a signifishycant amelioration of painful sensations

Most striking is the fact that by the time the dentist reached the third toothshyafter only a few minutes of this pain-driven self-hypnosis-the author saw a normal sequence of 4 receding annuli followed by swirling clouds of amorphous expanding phosphene even though the dentist was still using the drill contemporaneously This experience suggests that thalamic sleep rhythms can be voluntarily induced even when the subjects level of physiological arousal is high

SIMILARITIES WITH ATTENTION-INDUCED PHOSPHENES

REpORTED BY OTHER OBSERVERS

Taxonomies of phosphene images always include examples of simple geometric phosphenes with circular or semi-circular shapes (disks annuli or crescents) as

14well as formless phosphene mists 11 - There are also a number of anecdotal accounts that are relevant for example Friedman an opthamologist who studied entoptic images by introspection describes a similar sequence of annuli induced by sustained inward concentration Circular waves of blue color may be seen in the dark by the dark adapted retina They start at the

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 122

periphery and move inward toward the macula as a concentrically contracting solid circle disappear at the macula and begin again at the peripheryl)

A valuable but often-neglected resource of information about phosphene imagery is presented in the literature of religious mysticism Many mystics reported having seen translucent colored lights while absorbed in prayer or meditation A list of descriptions excerpted from self-reports is presented in Table 1 (These excerpts are representative of phosphene images that appear during states of calm and inward-oriented concentration they do not include images associated with paroxysmal raptures) These phosphene images exhibit a relatively limited set of shapes and colors the shapes are either circular (eg rings disks wheels suns) or formless (eg mists snow smoke) and the colors are usually a variant of either green or blue The phosphene visions of mystics display shapes and colors that are comparable to the images described by the author this and the many similarities in the behaviors used to induce phosphenes suggest that both sets of phosphenes have a common etiology

DISCUSSION

Whether the author uses self-hypnosis to induce phosphenes or experishyences them as hypnagogic images the threshold sequence of receding annuli has the same characteristics In both these

instances the antecedent behaviors involve a state of low physiological arousal combined with mental withdrawal from external stimuli These parallels suggest the hypothesis that phosphene displays are related to sleep-wake transitions

PART I RECEDING ANNULI AND THALAMIC SPINDLES

Mechanisms controlling the transition from waking to NREMS Based on the work of several research teams16-20 a consensus scenario for the generation of NREMS has emerged In this scenario NREMS is the product of three brain rhythms that interact with each other in thalamocorticothalamic circuits During the drowsy transition to sleep which in humans is called stage l NREMS the low voltage activity in the cortical electroencephalograph (EEG) still shows a pattern of intermittent desynchronization The polarization of

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 123

Table I Excerpts from self-reports of light visions by religious mystics

HEBREW MYSTICS the appearance of the wheels was like the gleaming of beryl and the four had the same form

their construction being something like a wheel within a wheel Ezekiel like a dome shining like crystal spread out about their heads And above the dome something

like a rhrone in appearance like sapphire Ezekiel a round Iodder like a full sphere rolling back and forth before him bright blue R Abulafia A glowing light clear brilliance A purple light that absorbs all lights R Moses de Leon

HINDU AND BUDDHIST MYSTICS a perfectly round beautiful deep-blue shape of a size appropriate to the center of a mandala as

if exquisitely painted of extreme c14rity Tsong Khapa a luminous revolving disc studded with lights a lotus flower in full bloom Gopi Krishna both my eyes became cemered When this happened a blue light arose in my eyes like

a candle flame without a wick and stood motionless in the ajna chakra S Muktananda

MUSLIM MYSTICS [like] chandelierssublime lights [like] stars moon or the sun Sharafuddin aI-Maneri its color is deep blue it seems to be an upsurge like water foom a spring Najmoddin Kobra visualize yourself as lying at the bottom of a well [looking up at the light of the opening] and

the well in lively downward movement Najmoddin Kobra the color green is the suprasensory uniting all the suprasensories Alaoddawleh Semnani the light rises in the Sky of the hean taking the form of light-gilling moons Najm Razi

CHRISTIAN MYSTICS his own state at prayer resembles a sapphire it is as clear and bright as the sky Evagrius descending like a bright cloud of mist like a sun round as a circle Simeon Neotheologos saw something in the air near him He did not understand the rype of thing but in some ways

it appeared to have the form of a serpent with many things that shone like eyes although they were not eyes Ignatius of Loyola

the soul puts on a green amilia [cape worn on shoulders beneath armor] John of the Cross [the almilla is like a helmet which] coverS all the senses of the head of the soul It has one

hole rhrough which the eyes may look upwards John of the Cross a round thing about rhe size of a rixdaier all bright and clear with light like a crystal H Hayen I saw a bright light and in this light the figure of a man the color of sapphireblazing with a

gentle glowing fire the three were in one light Hildegard von Bingen saw a b14zing fire incomprehensible inextinguishable with a flame in it the color of the sky

Hildegard von Bingen saw placed beneath her fuet the whole machine of the world as if it were a wheel She saw herself phced

above it her eyes of contemplation magnetized towards the incomprehensible Beatrice of Nazareth I saw the eyes I do not know if I was asleep or awake Angela of Foligno kind of sunlit winged being like a childs head beneath two little wings Abbess Thaisia laquobullbull round patterns small circles would expand and eventually dissipate only to be followed by other small

circles of light Philip St Romain an extraordinary circle of gold light pulsating against a deep violet background There were

always four or fille As soon as one would fode another would appear Philip St Romain

middotItalics added to mark words referring to (l) rings appearing in sets of four (2) amorphous shapes such as clouds or flames (3) circular or eye-like shapes (4) colors from the center of the visible spectrum (gold yellow yellow-green green bluish green) and (5) colors from the lower end of rhe visible spectrum (blue purple violet)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 124

cell membranes (Vm) has already begun to drop (hyperpolarize) in the thalamic reticular nucleus (RTN) a thin sheath of GABAnergic inhibitory neurons that acts as a pacemaker When the Vm of RTN cell membranes drops to approximately V m -60 millivolts (mV) RTN cells stop firing single spikes which are associated with waking states and instead begin firing highshyamplitude 7-14 Hertz (Hz) spike-bursts These bursts wax and wane over 1 to 3 seconds-hence the name spindle -and recur at 3 to 10 seconds Spindle volleys are relayed across the cortical mantle by thalamocortical (TC) sensory relay cells In human studies the primary criterion for onset of the first fullyshyestablished episode of NREMS or stage 2 sleep is the presence of globalized spindles in the cortical EEG

When spindle bursts from the RTN stimulate TC cells to fire in synchrony this synchronous bursting pattern overwhelms the normal capacity of TC cells to relay afferent sensory signals The loss of consciousness at the onset of stage 2 NREMS is thought to be caused by this blocking effect 21

While the RTN is firing spindle bursts through the thalamus another process is activated in the cortex large numbers of cells across the cortical mantle begin to oscillate at a very low frequency laquo 1 Hz)

The cortical slow rhythm referred back to the thalamus via corticothalamic circuits intensifies the hyperpolarizing effect of the RTN spindle bursts on TC cell membranes When V m -75 mV the TC cells begin to generate their own intrinsic calcium currents which further increases hyperpolarization At V m -90 mV the RTN neurons stop firing spindle bursts The TC cells continue to fire low-threshold calcium spikes in patterns which are controlled by the cortical slow rhythm The interaction of these two oscillations generates the delta waves (1 to 4 Hz) which are associated with stage 2 NREMS

In a study of sleep rhythms using the cortical EEG Uchida Atsumi and Kojima found that the mean number of spindles required to induce delta wave activity (that is to induce Vm = -90 mY) is 478 plusmn 162 spindles (from 3 to 7 spindles)22 The mean number of spindles in a volley remains the same for a single individual over multiple trials

Based on the consensus scenario for generation of NREMS we can predict that a phosphene image generated as an epiphenomenon of a thalamic spindle

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 125

Table II Dara show rhe degree of correspondance berween rhe pulse panerns of rhalamic spindles based on intracellular research and rhe sparioremporal panerns of receding annuli phosphenes induced by rhe author using a rechnique of self-hypnosis

Receding annuli phosphenes Thalamic spindle bursrs

Mean number of signals 4 annuli 487 (plusmn 16) bursrs

Sparial exrension vs Thin band 1 - 3 seconds durarion of signal ( 05 -15 cm)

Periodicity of signals 5 seconds 3 - 10 seconds

Simultaneity in LGNs Yes Yes

Point of entry Peripheral VF Ventral amp lareral LGN

Trajecrory Bilareral concentric Unknown

Rare of flow Cons rant rare Unknown

Signal-ro-noise rario High High (shorr bursrs) (sharp brighr discrere)

Termination of sequence Mrer 4 signals Mrer 487 (plusmn 16) signals

will present the following characteristics (1) a high-definition burst-like signal (2) that recurs within 3 to 10 seconds (3) that follows a trajectory compatible with having entered the LGN from the RTN (4) that has a predictable mean for the individual subject and a range that falls somewhere between 2 to 7 annuli and (5) that the spindles will terminate automatically

The temporal patterns of receding annuli and thalamic spindle bursts are similar Table II illustrates the close match between the timing of receding annuli phosphenes and thalamic spindle bursts The most striking similarities are the mean number of signals required to induce termination (4 annuli versus 487 spindles) and the interval between signals (5 seconds for annuli versus 3shyto-lO seconds for spindle bursts) Neither alpha theta nor beta waves present this kind of stereotyped temporal pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 126

T he spatial features of receding annuli are functions of geniculate anatomy A spindle burst moving through the LGN to the cortex will acquire certain distinctive spatiotemporal characteristics because of the

unique curvilinear and laminar anatomy of the LGN A drawing of a macaque LGN based on a clay model constructed by Le Gros Clark23 is shown in Figure 3 The primate LGN is composed of six sheets of cells or laminae that fold over a central hylus In macaques the hylus rises steeply as it extends rostrocausally forming a high arch at the posterior pole in humans the hylus is much more shallow but the functional anatomy is thought to be essentially

23 24the same in both cases - The geometry of the arch forces each lamina to bend so as to constitute in effect one-half of a conical surface and each lamina with its hemi-conical shape contains visual relay cells representing the contralatshyeral half of the visual field (VF) Operating as a pair the complementary hemishycones of the right and left LGN form the functional equivalent of a single conical surface which represents the entire VE This conical geometry of the paired LGNs means a burst of otherwise formless excitation will acquire a distinctive shape as it propagates through the laminae of the LGN Imagine a horizontal section moving along the surface of a cone from base to apex that moving section forms an annulus that shrinks in diameter as it approaches the apex but retains its annular symmetry throughout its trajectory

Figure 3 also includes drawings that show how Connolly and Van Essen24

converted the 3-dimensional structure of lamina 6 the largest and most dorsal layer into a 2-dimensional map Connolly and Van Essen used data obtained by Malpelli and Baker25 to superimpose a grid that specifies the areas in lamina 6 that contain TC cells representing various degrees of isoeccentricity in the VE We will use this map at a later point to show how the movement of a spindle wave through a pair of LGNs correlates with what appears in the VE

The location of the RTN relative to the LGN is also shown in Figure 3 The RTN spindle pacemaker is a thin sheath of GABAnergic inhibitory cells that extends along the surface of the whole posterior ventral thalamus not just the LGN This extension brings the RTN into close proximity with the portion of the LGN (lateral wing) that protrudes out from the main body of the thalamus Some of RTN wraps around and beneath the ventral edges of the LGN26 The RTN comes closest to the LGN in two areas along the ventral edges of the longest laminae (lamina 6 and 1) and along the edge of the lateral

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 127

DORSAL POLE DORSALPOIEA B

L1 L4 L3 L

DORSAL POlE DORSAL POIE (FOVEA)

G LATERAL WING

25

DORSAL POL (FOVEA)

10 _DIAL

20 WING

~

wing These areas contain TC cells that represent the far periphery of the VE If a spindle burst enters the LGN at locations where laminae are in closest proximity to the RTN-along the ventral edges-then the discharge of TC cells will begin in the most ventral portions of the laminae the regions that represent the far periphery of the VE This matches the phosphene sequence observed by the author

Our hypothesis about how this proximity between RTN and LGN affects the trajectory of spindle waves is illustrated in Figure 4 We propose that it is not possible for the author to observe a thin annulus of phosphene sweeping in from all 3600 of the peripheral VF unless spindle bursts exhibit the following

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 128

Figure 3 [facing page Drawings of primate geniculate anatomy and functional anatomy relevant to the generation ofphosphenes (A) Anterior view ofa macaque monkey LGN based on a clay model reconstruction by Le Gros Clark 23 (B) Posterior view ofthe same model showing 6 laminae folded over a central hylus to form lateral and medial wings with the hylus arching steeply upward near the posterior pole to shape the laminae into layers of hollow half-cones nested together Note that the lateral wing of the LGN is slightly larger than the medial wing so that in situ the lateral wing protrudes out from the main body of the thalamus creating a small knob visible during dissection 26 (C) Schematic drawing of an oblique section through median axis (also adapted from Le Gros Clark13 showing how the laminae fuse together at the anterior pole The afferent ganglion cell axons that form the optic tract (OT) penetrate through the anterior surface to reach their target relay cells in the laminae (D) Drawing of the most dorsal lamina-layer 6--separated from the rest of the LGN The geometric shape is a hollow half-cone so that right and left LGNs placed back-to-back form in effect a single cone Note also the position ofthe RTN shown here as a striped bar relative to lamina 6 The position of the striped bar shows that the RTN makes direct contact with lamina 6 at the edge ofthe lateral wing and also along the ventral edges (E - F) Schematic drawings adapted from Connolly and Van Essen24 that show how a 3-dimensional lamina-lamina 6--can be transformed into a 2-dimensional triangular figure lamina 6 is removed and its wings unfolded (E) creating a slightly asymmetric triangular figure (F) which is adjusted to an oblong shape (G) in order to superimshypose a grid matrix with minimal distortion The grid plots locations of TC cells that represent various isoelevations and isoazimuths in the VF locations derived from the experimental observations published by Malpeli and Baker 25 Note the relatively large amounts of laminar surface allocated to central vision (0 0

- 30 0) as compared

to peripheral vision (30 0 - 80 0)

characteristics (1) Spindle bursts must move simultaneously through both geniculate nuclei This pattern of movement is consistent with anatomical studies in primates that found axonal projections linking the right and left RTNs27-28 and with experimental studies in cats that found spindles appearing simultaneously in both right and left thalami 29 (2) Spindle waves must enter the ventral edges of the LGN first and move ventrodorsally in a highly coherent pattern-moving in effect as a standing wave This pattern of movement is consistent with in vitro experiments using sagittal slices from a ferret LGN where spindle waves originated spontaneously at the edge of a slice in an area which contains cells that represent peripheral vision then propagated toward that area of the slice containing cells that represent central vision in the ferret 3o

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 129

VF

PG BIlateral receptive lleJd of PVN YI(j Inward dmKooflality Adapled

0-- from Mortgr at at (1987)

V1

ibull t bull

RTN t t t t t t 1middot3 SECOlO BURSTS OF 7middot14 HZ SPiKES RECURRNG EVERY 3 10 SECONDS

To our knowledge the LGN is the only anatomical structure in the visual system that has the capacity of passively forcing a wave of excitation to flow across a conical surface thereby generating the sensation of a phosphene annulus that retains its symmetry as it shrinks in diameter The retina has a circular anatomy but it is not likely that the mechanical deformation of the retina would produce a wave that began simultaneously in all 3600 of the retinal rim nor that the symmetry of annular wave would be preserved as it flows inward toward the foveal region

The hypothesis presented here-that there is a structure in the visual system that imprints a conical shape on standing waves that move through it-explains

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 130

Figure 4 facing page Schematic drawing of contemporaneous events in selected regions of the visual processing hierarchy (A) The left and right RTNs fire spindle bursts simultaneously (B) The bursts pass through the right and left geniculate laminae as standing waves of depolarization entering from the ventral edges and moving ventrodorsally in parallel In order for the phosphene annulus to appear to be flowing at a constant rate the spindle wave flowing through the LCN must expand in width as it ascends ventrodorsally so that by the time the fill-in disk appears-when the center 30deg of the VF is covered by the phosphene annulus-the spindle wave must have expanded enough to activate relay cells in the most dorsal 50 of lamina 6 (C) Signals representing two complementary hemi-annuli are kept separate in the primary visual cortices (area VI) (D) Signals representing the two hemi-annuli are integrated into signals of a single annulus when they reach area PC in the posterior parietal cortex where the receptive fields of single parietal visual neurons have the capacity to register bilateral signals that exhibit opponent vector movement (that is signals converging from opposite directions along the central axes-as if an object were moving away from the viewer)46 Neurons in area PC also integrate wavelength (color) signals from the extrastriate visual pathway with signals about brightness motion and depth from the parietal visual pathway to compose a representation of an object in space-in this case of an annulus that appears to recede 32

the authors experience during MRI when he observed a continuous succession of receding annuli every 2 seconds in this view the energy of the electroshymagnetic bombardment when released during precessional relaxation flows through the geniculate laminae in the same way that the RTN spindle bursts do that is as a standing wave and thus the visual epiphenomenon is the same in both cases if the subject keeps the eyes focused straight ahead and the attention fixated In a study of phosphenes evoked by electricity in conjunction with hallucinogenic drugs Knoll Kugler Hofer and Lawder found that each subject sees specific kinds of phosphene at different frequencies and that these frequency-specific images are stable enough to be reproduced after six months31

They conclude that the tunability of the electrical stimulation frequenshycies within the EEG range to various definable phosphenes requires the existence of a resonance system One mechanism contributing to that resonance system may be the functional anatomy of the LGN

The colors of receding annuli as functions of geniculate laminar anatomy The colors of receding annuli phosphenes are consistent with the patterns of discharge spindle waves can be expected to stimulate as they move through

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 131

geniculate laminae As shown in Figure 5 the six laminae differ (1) in the types of wavelength signals relayed (2) in physical size and (3) in the area of the VF represented 24-25 Only 4 out of 6 laminae Cparvocellular layers 3shy6) contain TC cells that relay wavelength signals the other 2 laminae (magnocellular layers 1 and 2) do not encode wavelength Among parvocelshylular laminae only lamina 6 the longest and most dorsal layer contains TC cells that can represent the far periphery of the VF (from 800 to 50deg of isoeccenshytdeity) therefore when the spindle wave enters the peripheral VF only those wavelengths relayed by lamina 6 will participate in composing a cortical lightness record (See Zeki)32

I n lamina 6 ganglion cell axons arriving from the retina carry two kinds of wavelength signals (1) center-ON signals from medium-wavelength cones (M-cone center-ON) and long-wavelength cones (L-cone centershy

ON)33-35 Using the cone spectral sensitivity curves (adapted from Marks et al 36) we average the wavelengths that elicit maximal responses for M-cones (535 nanometers) and L-cones (520 nm) which yields a mean wavelength value of 550 nm In humans this wavelength generates a sensation of green or yellowshygreen the sensation observed by the author

As the spindle burst moves ventrodorsally it reaches the dorsal areas in the geniculate laminae which contain TC cells representing the central 0deg to 20deg of isoeccentrieity in the VE All 4 parvocellular laminae have TC cells which are potentially capable of representing this central region of vision but the authors observation that the color of the filling-in disk changed from green to blue implies that in the early years of phosphene induction the spindle wave must have remained close to the surface of the LGN stimulating only laminae 5 and 6 which generates a sensation of yellow-green When the fill-in disk was observed to change color from green to blue the spindle wave must have been rechanneled so that it began to penetrate below laminae 5 and 6 and to activate laminae 3 and 4 the only laminae that relay blue-sensitive signals (Sshycone center-ON signals)3 In light of the authors MRI experience it seems likely that a spindle wave requires a minimum of 2 seconds to reach the blueshysensitive cells of laminae 4 therefore during MRI when the receding annuli disappeared after 2 seconds half the normal duration the fill-disk had a green color even though it had long since change to blue in other induction settings with a 4-second trajectory

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 132

A REPRESENTATION OF THE VISUAL FIELD IN EACH LAMINA

orooqUtftc O-u OCIJ1SALfIOLI (I01flAj

0

10

20

30

40 n50 Of

60

70

20 loO 1Mgr_ II~ o UIpoundAS65 mn1MY-o actlvncL ~~~r

Jll-COMcetlImiddot~

II LAYERSU 3 GatQYancetl~ (1) ucon ceom-oyenF (2)l~cen()FF 3) ~ cenloH

II~ cng1loqctWIIIfNla

iICINe -- (t81Otdb1t1d~OH (2)~

80

B CONE SPECTRAL SENSITIVITY CURVES

S-COHS

WAVIlLllNG1llS OF UGHT IH NANOMllTERS (NM)

Figure 5 Phosphene color as a function of ganglion cell distribution in parvocellular laminae (Aj Schematic drawing ofthe proportion ofthe VF represented in each laminae The proportions shown here are based on the work of Connolly and Van Essen24 The

far periphery of vision (50 0 to 80 0 of isoeccentricity) is represented in only two laminae-laminae 1 and 6-and of these two only lamina 6 is a parvocelLular lamina capable ofencoding wavelength signals Therefore only those wavelengths relayed by lamina 6 will participate in forming a cortical lighmess record for the far periphery of the VP (B) Cone spectral sensitivity curves (adapted from Marks et al)36 Using these cone sensitivity curves we can estimate the sensation stimulated by a spindle wave moving through lamina 6 by averaging the wavelengths that elicit maximal responses for M-cones (535 nanomeshyters) and L-cones (520 nm) which yields a mean wavelength value of550 nm In humans this generates a sensation of green or yellow-green the sensation observed by the author when the receding annulus enters at the far periphery of the VP For a calculation of the cortical lightness record when a spindle wave moves through 20deg to 0deg ofthe VF stimulating all 4 parvocelfular laminae see the text and Figure 6

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 133

Once the spindle wave penetrates to laminae 3 and 4 it may activate all 4 parvocellular laminae stimulating TC cells to send contradictory wavelength signals for the same retinotopic location the signals sent from laminae 4 and 3 will encode blue light (S-cone center-ON plus M-cone center-OFF and Lshycone center-OFF) while the signals sent from laminae 5 and 6 encode yellowshygreen light (M-cone center-ON plus L-cone center-ON) This kind of contrashydiction does not occur in normal retina-based perception where light energy striking the retina is structured by the retinas center-surround and colorshyopponent organization to encode only one set of wavelength signals for each spatial locus 32 In Figure 6 we estimate the cortical lightness record that results when contradictory wavelength signals compete to be represented in consciousshyness Our calculations suggest that the outcome will be a mean wavelength which in humans elicits a dark blue or violet sensation

PART II AMORPHOUS PHOSPHENES amp THALAMIC DELTA ACTMTY

M echanisms controlling the transition from spindle bursts to delta activity In the consensus scenario for the generation of NREMS16-20 we noted that the RTN shifts to firing spindle bursts

when polarization of thalamic cell membranes drops to V m = - 60 mV At the same time cortical cells begin oscillating with a synchronous slow rhythm laquo 1 Hz) Both processes further decrease the Vm of TC cell membranes When Vm = - 75 mY TC cells begin to generate their own intrinsic calcium currents which also decreases V m At V m = - 90 mV RTN neurons stop firing spindle bursts At the same time the TC cells begin firing low-threshold calcium spikes in alternation with after-hyperpolarizations (LTS-AHP) Because sensory relay neurons in the LGN are not linked to one another by locally projecting axons the firing of one TC cell does not excite its neighbor However a lack of local connectivity does not mean that TC cells occupying the same laminae release their AHP-LTS calcium spikes in a random distribshyution rather spikes are released simultaneously by groups of cells in synchrony with the advent of the cortical slow wave In effect the distribution of LTSshyAHP spikes firing in the LGN is determined by the spatial propagation of the cortical slow wave Thus the delta wave (1 to 4 Hz) activity detected by cortical EEG during NREMS is a product of the interaction between the AHP-LTS calcium spikes released by TC cells and the cortical slow rhythm

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 134

CORTICAL PROCESSING OF CONTRADICTORY

WAVELENGTH SIGNALS

KEY _ Cells firing

cJ Cononol firing

Assume that as a spind6e wave moves through the LGNlt fires simultaneously aU the TC cells that represent a particular reUnoshytopic locus (x y) in each of the six laminae As a result cortical cells engaged In the higher level processing of visual signals will receive more wavelength signals representing retina locus (x y) than are generated by normal perception laquo and some of these afferent wavelength signals may contradict other signals arriving simultaneously

CORTICAL LIGHTNESS RECORD SlgnalSell

Intemal contradictions not congruent wilt pre

SmiddotON eristing neuron neta

s bullbull M-ON LmiddotON

3 bullbull M-OFF + L-OFF

a-ON 12

ROD-ON

No Internal eonlradlemiddot

--------1I =~8b~~~~~~~t signals

3+4

~ --OFF Excludes 6 Of 7 $J9n18

1+2 B-ON I

IWmiddotHmiddotI Signal Sell

1111111 No Intern1 conlrfldlcshy lion

Exelvdta 4 out of 7 efshy

bullbullbull bullbullbull ferant signals

No Intern1 contradic_ tionnee S-ON BshyOH and ROO-ON can all be coacllve at low lImlnance levels nef Ihe rod-eone break

ExchJde$ only 2 Ollt of 7 afferent signals

Figure 6 Selection of competing wavelength signals based on neuronal group selection This thought experiment is based on Edelman sconcept ofneuronal group selection 73 We assume that all possible combinations ofsignals will form sets and that all signal-sets will compete to make the most efficient match with pre-existing neuromd networks that have been forged over years ofnorma reti1U1-based perception We also assume that pre-existing neural networks are most likely to expedite those sets that satisfY 2 criteriI (J) the signals in a set do not contradict each other and (2) fower signals are excluded than in the other sets that satisfY the first criterion In our analysis Set 4 wins the competition because it does not contain internal contradictions and excludes fower signals (2 out of 7) than Set 3 excludes (4 out of7) It is not an internal contradiction that Set 4 contains both rods and cone Signtlls in normal retina-based perception when luminance levels approach the rod-cone break S-cone center-ON receptors send signas as do rod receptors and there is even evidence that rod activity may actually drive S-cone activity even after luminance levels foIl below the rod-cone break74 To calculate the cortical lightness record for Set 4 we average the wavelength that elicits maximal responses foom rods (511 nm) and for Sshycones (430 nm) which yields a mean wavelength of 470 nm which in humans results in a dark-blue or violet sensation

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 135

The cortical slow rhythm is an example of a generic pattern of neuronal excitashytion that occurs in large networks of neurons linked by local projections A recent experiment by Maeda Robinson and Kwana38 shows that networks of locally-connected neurons spontaneously generate periodic synchronized bursts of calcium transients that propagate across the network in an expanding spatial wave a pattern that represents a stable mode of firing towards which these neuronal networks relax following perturbations for example by electronic stimulation or by drugs Understanding the characteristics of these waves is an important prerequisite to understanding the mechanisms that produce the amorphous phosphene images as a visual epiphenomenon

To study the spontaneous periodic synchronized bursts the researchers prepared cultures of dissociated cortical neurons and allowed them to mature for several days in vitro (DIV) After 3 to 4 DIV when concenshy

trations of extracellular magnesium were low electrodes began to detect spontaneous synchronized bursts of low frequency calcium transients (between 01 and 1 Hz) that originated in different locations on the sheet every 10 to 20 seconds and spread across the sheet of cells at a relatively slow speed averaging 50 mmsecond The researchers could not predict where a wave would originate or where it would expand rather the initiation and expansion of waves was generated by spatial and temporal summation of a continuous random background of synaptic inputs including miniature spontaneous synaptic events but the pattern was not random since waves propagated sequentially from electrode to electrode as each local group of neurons charges up its neighboring nontefractory areas rather than in a random sequence of regions38

The excitability of the cells in the sheet determines the probability first that there will be a synchronous burst and second that it will spread in a particshyular direction Cells become more excitable as the cultures mature which means the refractory intervals between successive bursts were much shorter in mature cultures (gt 30 DIV) than in early cultures laquo 7 DIV) Some cells became so insensitive to inhibition that they continued to fire bursts even when extracellular concentrations of magnesium were relatively high Finally there were refractory periods of 5 to 10 seconds during which no bursts occurred even when an electrical stimulus was applied This refractory interval for cultured networks is slightly longer than the refractory interval observed of the cortical slow wave in vivo which 25 to 4 seconds 18- 19

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 136

Based on the observations about cortical slow waves we can predict that phosphenes generated as epiphenomena of delta wave activity will present the following signal characteristics (1) signals that appear at unpredictable locations in the VF (2) signals that expand and diverge asymmetrically following unpredictable trajectories which may encompass large areas of the VF (3) signals that move relatively slowly (50 mmsec) (4) signals that recur with a period of 2 to 4 seconds reflecting entrainment by the cortical slow wave (5) signals that do not terminate automatically after a predictable number of cycles

The spatial patterns of phosphene mists and thalamic delta waves are similar The spatiotemporal characteristics of amorphous phosphenes match the pattern of wave propagation associated with periodic spontashy

neous synchronized bursts in large neuron networks the amorphous phosphenes enter the visual field at unpredictable locations expand and diverge asymmetrically with a slow steady rate of flow follow trajectories that are unpredictable and exhibit a refractory interval The amorphous mists do appear to have a periodicity although the author is unable to sustain the vision while also counting the seconds therefore he is unable to determine if it compares to the period of the cortical slow wave (25 to 4 seconds) but his impression is that it feels roughly the same as as with receding annuli which recur at 5 seconds Also the refractory interval feels as if it decreases as the induction session is extended These similarities suggest that the amorphous phosphenes are generated by stage 2 NREMS delta wave activity which is an activity governed by the reverberation of the cortical slow wave in thalamoshycorticothalamic circuits The cortical slow wave is referred to the LGN where it modulates the firing of visual relay cells in the laminae and since relay cells do not have local dendritic connections the expansion of a wave of depolarshyizations moving from one relay cell to the next across in the laminar surface will mirror at least in part the expansion of the cortical wave that is spreading contemporaneously through locally-connected cortical cells

PART III RETENTION OF CONSCIOUSNESS

In a normal transition to NREMS the volley of synchronous spindle bursts that marks the onset of stage 2 NREMS overwhelms the normal firing pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 137

of thalamocortical cells preventing their relay of afferent sensory signals and inducing a loss of consciousness21 But the loss of consciousness cannot be timed precisely using cortical EEG the thalamus is too remote for the onset of spindling to be reliably detected by scalp electrodes39 In experiments with cats where electrodes could be implanted in the thalamus researchers found that spindling often reached peak levels of activity in the thalamus-a level of activity consonant with stage 2 NREMS-at a time when the cortical EEG was still showing intermittent desynchronizations a pattern characteristic of the drowsy stage 1 transition not a fully-established stage 2 NREMS episode4o

In other words there is a short period of time in which the synchronous rhythms of stage 2 NREMS are installed in the thalamus but not in the cortex where cortical neurons continue to depolarize in response to afferent sensory signals

T his finding suggests a possible explanation for the authors ability to retain consciousness while spindle bursts are sweeping through the LGN if he is able to extend the duration of this time lag between

the onset of spindling in the thalamus and spindling in the cortex if he is able to stimulate the visual cortices in such a way that they continue to depolarize then he may be able to keep on processing visual signals-to remain visually aware-even after the non-visual thalamus and non-visual cortex become entrained by synchronous sleep rhythms The authors induction technique includes several behaviors which are known to enhance the responsiveness of visual neurons-eye movements attentive fixation and an attitude of expectancy

Effects of eye movements and attention on the LGN Sustained convergence causes periorbital proprioceptors to send excitatory feedback directly to the LGN41 Also convergence further enhances the excitability of geniculate cells by stimulating the superior collicus (SC) which sends its own excitatory signals to the LGN42-43 These signals from the SC are known to selectively enhance the excitability of visual relay cells that represent the periphery of vision44 We know in the authors case that the SC is being stimulated because he is able to keep on fixating an ability which would normally be lost during the transishytion to NREMS45 The ability to fixate can be retained however if the SC is stimulated (even if stimulated during NREMS)46

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 138

Effects of eye movement attention and expectancy on the primary visual cortex The PET study of mental imagery by Kosslyn et al 3 showed that even a baseline resting state of relaxed immobile expectancy can generate signifishycant increases in neuronal activity in the primary visual cortices Further increases can be induced by sustained eye movements

A sustained convergence will release a stream of ponto-geniculo-occipital (PGO) waves These PGO waves called eye movement potentials or EMPs last only as long as the eye movement1747 whereas the PGO waves associated with rapid-eye-movement sleep (REMS) fire continually for the duration of the REMS episode Both REMS-related PGO waves and EMPs have the same desynchronizing effect on the visual pathways they move through the LGN depolarizing the thalamocortical cells which relay the signals to cortical neurons The responsivity of neurons in the primary visual cortices is enhanced by the stimulation of PGO waves 1747-49 If the passage of EMPs causes the genicushylate relay cells and their cortical targets to depolarize regularly then a volley of 4 spindle bursts moving through the same pathways will register as just another series of depolarizations in effect the spindle bursts are processed by the visual system as if they were sensory signals sent from the retina rather than an event stimulated by endogenous mechanisms

T he impact of eye movements and ftxation on the parietal visual cortex Convergence and attentive fixation will also enhance the responsiveness of light-sensitive parietal visual neurons (PVNs) in area PG of the

posterior parietal cortex 50 In experiments where monkeys are trained to fix their attention on a screen-and to keep on fixating even if no targets appearshythe excitability of these light-sensitive PVNs increases by as much as 350 51

52-53Responsiveness is also facilitated by the angle of gaze Also area PG is the first region in the visual pathways containing individual neurons with the capacity to respond to large bilateral stimuli moving in opposite directions along the central meridians of vision (opponent vector motion) 853-55 Facilitation of PVNs in area PG has the effect of sensitizing the subject to bilateral opponent vector motion and this is especially true if the movement appears in the periphery of the VE 8

Intracortical ampliftcation and feedback to the LGN When PGO waves and signals from the SC arrive in the primary visual cortex they may be relatively weak however weak signals can be amplified by reverberating in large networks

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 139

of cortical cells linked by local projection 56 There are nine times as many excitatory links among cortical cells as there are projections from the visual cortex to the LGN an imbalance which suggests leads Suarez Koch and Douglas to propose that geniculate input provides only a minor fraction of the excitatory input the majority originating in neighboring and recurrently connected cortical cells57 If the excitabiliry of cortical neurons is slightly higher than normal then this process of amplification may continue even after the LGN signals that initiated the reverberation are no longer being transmitted by the LGN ( a hysteretic mode of operation) 57

Feedback from hyperexcited cortical neurons will stream back to the LGN via corticogeniculate projections which outnumber geniculocortical projections ten-to-one One effect of this feedback is that the LGN is

able to absorb large amounts of information flowing back from the cortex 58

As signals reverberate back and forth in thalamocorticothalamic circuits a matching process takes place those geniculate relay cells that fire in patterns consistent with the firing patterns of active cortical cells will have their responshysivity enhanced while those geniculate cells that fire in patterns not consistent with cortical cells will be suppressed 59

Preservation of consciousness by selective facilitation of the visual pathways By combining all of the facilitatory effects produced by the authors eye movements and attentive fixation-(l) stimulation of the LGN by feedback from periorbital proprioception both directly and indirectly via the SC (2) the release of PGO waves (EMPs) that facilitate neurons in the LGN and primary visual cortex as they pass (3) the facilitation of the primary visual cortex by a state of relaxed immobile expectancy (4) attentive fixation and angle of gaze that facilitate PVNs in area PG (5) intracortical amplification of signals received from the LGN and (6) corticogeniculate feedback that stimulates the LGN-we delineate a circuit of enhanced excitability that extends from the LGN through the post-geniculate visual heirarchy to area PG where signals are integrated into representations of objects

The hyperexcitability of neurons all along the post-geniculate visual pathways creates conditions in the visual cortices which are similar to those present during EEG-desynchronized states of waking and REMS Therefore neurons in the visual pathways are too excitable to be entrained by synchronous bursting

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 140

patterns when spindle waves move through them instead the spindle bursts stimulate visual neurons to depolarize and then recover as happens in response to afferent sensory signals during waking states It is important to note that for this to occur none of the constituent neuron assemblies is required to perform an abnormal operation the abnormality is a function of the authors intent to activate contemporaneously neuron assemblies that would not normally be co-activated

PART IV HYPNOTIC ANALGESIA

Manipulation of spatial attention as a method for alleviating pain sensations In a theoretical article on the neurophysiology of hypnosis Crawford and Gruzelier60 propose that variations in hypnotizability are function of variability in the efficiency of the frontolimbic (anterior) attentional system in humans high-hypnotizables are better able to sustain focused attention on a task and to ignore extraneous stimuli than are low-hypnotizables

I na related empirical study that compares the use of attention by subjects with high versus low hypnotizability Crawford Brown and Moon61 report that highly hypnotizable persons continue to show physiological reactivity

while cognitively not perceiving the painful stimuli Through disattentional processes they can dissociate themselves from the awareness of pain The authors phosphene induction behaviors-and the cutaneous analgesia he experishyences-appear to involve the same kind of behaviors that is a mobilization of frontolimbic attention used to withdraw attention from external stimuli and to concentrate it on internally-generated phosphene images This suggests the hypothesis that the mechanisms that generate phosphenes might also produce hypnotic analgesia There are several ways that visual signals and pain signals might interact to produce this analgesia

Competition between pain and vision signals for limbic registration The fully-developed sensation of pain requires integration of rwo kinds of informashytion Signals that encode the location and intensity of a noxious stimulus (nociceptive signals) are relayed via the thalamus to the somatosensory cortices which registers only the sensory-discriminative aspects of pain perception62 before reaching consciousness the nociceptive signals must be sent to the limbic

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 141

system where they are linked with signals from long-term memory that encode the affective significance the stimulus has acquired for that individual Studies of brain metabolism show this linking of somatosensory information with limbic associations takes place in the anterior cingulate (CG) and anterior insula62-64

PET studies also show that the anterior CG is activated when subjects shift their spatial attention in response to expectations as to where

66stimuli will next appear65- This is precisely what takes place during the state of immobile expectancy that induces phosphenes Since visual signals and nociceptive signals both require limbic enhancement which is only possible if they get access to the anterior CG there might be conditions in which the two types of afferent sensory signals have to compete for that access In a theoretical article on the mechanisms of attention Posner and Rothbart67

propose that visual signals can interfere with nociceptive signals by blocking access to the anterior CG As behavioral evidence they cite studies showing that when young infants make distress calls they can be distracted by the presentation of a new visual stimulus We have shown the evidence of such control at about three months Orienting to visual events can be employed to quiet or calm negative vocalizations However the distress appears to be maintained and reappears when the infants attention to the stimulus is reduced Caregivers also report the use or visual orienting to block overt manifestations of distress at about this age 67

The effects of disattention on the somatosensory cortices If there is a competition between visual signals and nociceptive signals for access to the anterior CG it is likely that the competition will be affected by the relative volume of signals received A recent study suggests that focusing attention on internally-generated visual stimuli may reduce the number of nociceptive signals relayed by the somatosensory cortices Drevets Burton Videen Snyder Simpson and Raichle68 have shown that the mere anticipation of a touch at a specific cutaneous site increases the flow of blood to those cortical somatosenshysory neurons that are linked with that site where touch is expected and decreases the flow of blood to neurons linked with sites where touch is not expected In this experiment the researchers designated touch as the behaviorally significant sensory stimulus but their findings suggest that the outcome could be reversed if the instructions were reversed if subjects were

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page J42

instructed to direct attention away from a cutaneous site where a noxious stimulus was being applied if they were instructed to relax close their eyes and concentrate on the play of phosphenes in the visual field as the behaviorally significant sensory stimulus then it would be reasonable to expect that the flow of blood would decrease to the somatosensory neurons linked with the cutaneous stimulus and that the flow of blood would increase to the visual cortices The decrease in blood flow to somatosensory neurons implies less neuronal activity which implies that fewer signals are being sent forward to the anterior CG than would have been sent if instead the subject were treating the touch as the behaviorally significant sensory stimulus If fewer pain signals arrive at the anterior it is reasonable to infer that the conscious experience of pain will be muted by the diversion of attention to internal visual stimuli

Differential impact of sleep rhythms in the visual and nonvisual thalamus There is another mechanism that might also contribute to the analgesic effect of inducing sleep rhythms PET studies show that

the thalamus is involved in the relay of nociceptive signals to the cortex63 although some confusion remains about which kinds of signals are relayed by which subregions in the thalamus62 One thalamic site clearly identified by anatomical studies as a relay for nociceptive signals is the ventroposterior lateral nucleus (VPL)69 If synchronous sleep rhythms are active in the thalamus we can reasonably expect that the VPL will itself be entrained by synchronous oscillations and that it will relay the sleep rhythms to somatosensory cortices Relay neurons in the VPL are not stimulated by feedback from eye movements and fixation as are relay neurons in the LGN which suggests that sleep rhythms may impede the relay of nociceptive signals via the VPL but not the relay of visual signals via the LGN

Brain waves associated with anesthesia and NREMS The hypothesis presented here-that consciousness can be preserved despite the presence of NREMS activity-is consistent with a recent report that the kinds of fast brain waves which are normally associated with conscious states are also present during NREMS and anesthesia two states which were thought to involve minimal brain activityJo Another recent study found that there is a close resemblance between the slow brain waves that appear during NREMS and those that appear during certain types of anesthesia71

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 143

bull bull bull

CONCLUSION

In this paper we have presented evidence supporting the hypothesis that phosphene images can be generated as an epiphenomena of thalamic spindle bursts and delta wave activity normally associated with NREMS The prereqshyuisites for inducing these sleep rhythm phosphenes are relaxed immobile expectancy sustained convergence and attentive fixation of an undifferentiated visual field Our hypothesis provides a necessary and sufficient explanation for the authors induction of phosphenes and perhaps also for the generation of phosphenes reported to appear spontaneously during the drowsy transition to sleep (hypnagogic states) during sensory deprivation or during certain kinds of prayer or meditation all of which involve a similar state of relaxed immobile expectancyJ2

CORRESPONDENCE Philip T Nicholson bull 52 Norfolk Road bull Chestnut Hill MA 02167

REFERENCES amp NOTES

1 M 1 Posner Modulation by Instruction Nature 373 (1995) pp 198-199 2 J Reissenweber E David amp M pfotenhauer Investigations of Psychological Aspects of

the Perception of Magnetophosphenes and Electrophosphenes Biomedizinische Tecknik 373 (1992) pp 42-45

3 S M Kosslyn W L Thompson 1 J Kim amp N M Alpert Topographical Representations of Mental Images in Primary Visual Cortex Nature 378 (I995) pp 496-498

4 P E Roland amp B Gulyas Visual Memory Visual Imagery and Visual Recognition of Large Field Patterns by the Human Brain Functional Anatomy by Positron Emission Tomography Cerebral Cortex 51 (1995) pp 79-93

5 H Benson The Relaxation Response (Morrow New York NY 1975) 6 ] H Schultz amp W Luthe Autogenic Training a Physiological Approach to Psychotherapy

(Grune amp Stratton New York NY 1969) 7 E Jacobson Progressive Relaxation (University of Chicago Press Chicago IL 1938) 8 M A Steinmetz BC Motter C] DuffY amp V B Mountcastle Functional Properties

of Parietal Visual Neurons Radial Organization of Directionalities Within the Visual Field Journal ofNeuroscience 71 (1987) pp 177-191

9 R R Edelman Magnetic Resonance Imaging of the Nervous System Discussions in Neuroscience 71 Elsevier Science Amsterdam (I990) also J H Newhouse amp ] I Wiener Understanding MRI 1st Ed (Little Brown Boston MA 1991)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 144

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

0- 05 sec 10 sec 15 sec

20 sec 25 sec 30 sec

Figure 1 Schematic drawings ofreceding annuli phosphenes At first there is a sensation of movement inward from 360 0 in the periphery of vision then a bright thin yellowshygreen phosphene annulus sudden~y illuminates at about 80 60 of isoeccentricity The edges ofthe annulus are well-defined but more diJfose than this computer drawing program can depict-like a wellformed smoke ring The annulus preserves its symmetry as it shrinks steadio in diameter at a constant rafe offlow creating the illusion that it is receding toward the center of vision At 2 seconds the empty space inside the annulus fills abrupto with a disk ofbrighter phosphene At 4 seconds the image disappears into the centerpoint At 5 seconds another annulus sweeps into the periphery The author sees a total of4 receding annuli

of 1 second then the next wave appears at the periphery of the VE Midway in the trajectory-at 2 seconds-the empty interior of the annulus fills abruptly with a disk of slightly brighter phosphene A sequence of annuli usually terminates after 4 images although the number of annuli can be increased by diverting the attention for a moment and then refocusing

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 116

While the color of the annulus has remained the same over time the color of the filling-in disk changed after about two years of intermittent phosphene induction from yellow-green to blue The change began with tiny flecks of blue flashing amid the green just as the disk disappeared Over a period of several weeks the amount of blue expanded and appeared earlier in the fillshysequence Within a month the entire fill-disk was blue

The shrinking annuli create a psychological illusion of a ring of light receding toward a distant point in 3-dimensional space and pulling the attention into a vortex or paradoxically the same progression can create a sensation of falling backwards an illusory motion that resembles an effect produced by optic flow Motion in the visual periphery elicits in the stationary observer an illusion of self-motion (vection) indistinguishable from real motion The illusion of vection is compelling for it dominates contradictory proprioceptive signals For example subjects presented with optic flow consistent with backward self-motion perceive backward motion even if they ate actually walking forward 8

T he same receding annuli appear spontaneously as hypnagogic images while the author is reclining and waiting for sleep The receding annuli appear whenever the authors mind and body are relaxed his eyes closed

and his attention focused straight ahead-essentially the same behaviors used for self-hypnosis-but in the hypnagogic context virtually no effort is required the receding annuli feel as if they were released spontaneously not induced If the author is not relaxed or if he is distracted by a headache or importuning thoughts then the luminous receding annuli do not appear Instead the author loses consciousness abruptly at the onset of NREMS

AMORPHOUS EXPANDING PHOSPHENES

(A) loCAL RANDOMLY-DISPERSED EXPANDING WAVES Figure 2(A) illustrates one kind of amorphous phosphene mist that appears after the receding annuli sequence terminates These phosphenes are small amorphous swirls of yellowshygreen that coalesce suddenly at unpredictable locations in the VF and expand for a second or two then fade into the background There are often several images drifting in the visual field at the same time each in a different stage of evolution and the density of the phosphene seems to vary with some areas appearing thin and translucent others more opaque-like puffs of smoke that

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 117

10 seconds 15 sec 20 sec

25 Bee 30 sec 35 sec

expand and curl aimlessly then dissipate Because these waves are so unpredictable and formless the author is unable to predict the mean number of signals per episode the period between signals the site of entry or exit or to define a typical trajectory other than in the abstract generic manner used above The signal-to-noise ratio in these phosphenes is very low since phosphene stands out against the background there clearly is a signal but this signal presents so little pattern that it is essentially a form of phosphene noise These localized pulsations may continue for several minutes but usually within a minute or two they are superceded by the type of amorphous wave described next

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 118

Figure 2 [focing page Schematic drawings of of amorphous expanding phosphenes (A) Brief randomly-dispersed localized pulses These phosphenes are the first to appear after the receding annuli They coalesce at unpredictable locations in the IF expand asymmetrically for a second or two then dissipate into eigengrau before there is time to extend very for beyond their locus of origin (B) Periodic unidirectional amorphous expanding waves These phosphene waves enter the periphery ofvision from one hemifield presenting as a loosely-defined crescent (hemi-annular) cloud that mirrors the curvature of the peripheral rim The leading edge of the wave expands and flows across the vertical meridian into the opposite hemified swirling around the periphery curling inward and merging while at the same time the trailing edge ofphosphene dissipates rapidly in those regions over which the wave has already passed like mist or smoke evaporating in air The author is unable to time these waves but their duration fiels roughly the same as for receding annuli ie about 4 seconds Waves appear one after another in a cluster with a refractory period between clusters during which no waves appear After a prolonged session ofself-hypnosis the phosphene may not completely dissipate between successive waves in which case the residual phosphene accumulates in a vaguely-circular cloud shape with a small area its center that undergoes continual perturbation the phosphene pulls back leaving a small Mrk circle at the center of the cloud then fills back in then pulls away again ebbing and flowing in like manner until the cloud dissipates At this stage the image resembles an eye with a phosphene iris and a dark inner pupil (C) Twoshytone phosphene During a prolonged session the phosphene at the very center of the amorphous cloud becomes much brighter more fine-grained almost opaque with highly saturated color When a hole (pupil) appears in the center ofthe cloud forming an eyeshyimage the brighter phosphene becomes a thin bright rim lining the Mrk hole from this bright inner rim tiny promontories ofbright phosphene flare out into the Mrk hole twist and coil and collide with other flares forming webs and momentarily filling-in the Mrk hole or receding back into the rim The two-toned phosphene does not only appear in conjunction with the eye-shape clouds it also manifests at the center ofa variety ofelusive ever-changing shapes It is always restricted to the area offoveal vision

(B) PERIODIC UNIDIRECTIONAL AMORPHOUS WAVES These phosphene waves sweep in from one hemifield as shown in Figure 2(B) Often the wave has a vaguely crescent shape at the outset that conforms to the concave curvature of the peripheral VF then the crescent shape gives way as the wave expands rapidly in divergent directions flowing smoothly across the vertical meridian to envelop those regions of the VF that have not yet been illuminated As the leading edge of the wave expands the rear edges are already beginning to dissipate The swirling movement and the contraction of outer boundaries leaves a cloud of phosphene near the center of the VE This cloud may dissipate rapidly or it may persist for several seconds during which a pertur-

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 119

bation takes place at the center of the cloud the phosphene ebbs away from this region leaving a tiny dark hole then the phosphene fills back in then it ebbs and fills again-a fluctuation that continues as long as the phosphene cloud is visible During the perturbations the phosphene vaguely resembles the iris of a human eye with an interior dark space as its pupil This eyeshyimage is seldom symmetrical and its boundaries are always changing

(c) TWO-TONE PHOSPHENE When the phosphenes are induced over a prolonged period of time the phosphene in the central region representing foveal vision presents a more intensely bright more opaque (finely-grained) character than the rest of the cloud as shown in Figure 2(C) When this brilliant opaque phosphene appears as part of an eye-image it forms a thin rim surrounding the pupiL From this rim flares jut out into the dark pupil space coil about merge or recede back into the rim

The periodic unidirectional amorphous waves do not terminate after a stereoshytyped sequence they can be evoked over prolonged rime periods if the autohypshynotic behaviors are maintained The author is unable to retain the vision of these amorphous waves while simultaneously counting the number of seconds elapsed it is his impression however that the duration of amorphous expanding waves feels about the same as for receding annuli that is a duration of about 4 seconds per wave The amorphous waves usually appear in clusters followed by a refractory interval during which no phosphenes appear even if induction behaviors are sustained

PHOSPHENES SUPERIMPOSED ON ExTERNAL OBJECTS

The author can observe amorphous phosphene images with his eyes open if he is in a room dark enough that colors cannot be distinguished or if he is

in a lighted room but one where he can keep his eyes diffusely focused on a relatively undifferentiated surface such as a wall or ceiling with a light and uniform color and no distracting decorative adornments In open-eye viewings phosphenes appear as faint translucent waves of yellow-green mist

superimposed over the surface or in the dark space that fills the darkened room If the author attempts to focus on the features of external objects the phosphenes disappear

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 120

RECEDING ANNuLI EVOKED BY MAGNETIC REsONANCE IMAGING (MRI)

A s a patient undergoing an MRI scan the author observed an unusual sequence of receding annuli He was not relaxed as in a normal induction but rather anxious about his medical condition and about

being confined in the narrow MRI tube To keep calm he concentrated on breathing slowly and stared straight ahead While the sound of MRI machine was audible the author observed a stream of receding annuli that differed from the usual sequence (self-induced and hypnagogic) in three ways (I) the MRI annuli did not terminate at 4 cycles but continued for as long as the author kept his attention focused (2) the MRI annuli were only yellowshygreen in color even though in other inductions the fill-in disk had already changed from green to blue and (3) MRI annuli completed their trajectoshyries in half the normal time disappearing in 2 seconds instead of 4 An interval of 2 seconds between radio pulses is often selected as optimal interval for capture of the signals emitted by hyperexcited atoms in the subjects body

10during the precessional relaxation 9- These observations suggest that energy released in the wake of the radio bombardment during MRI moves through the LGN as a standing wave in the same way that spindle bursts move but that the 2-second duration of the MRI wave is not long enough to activate the neurons that generate a blue sensation

THE ANESTHETIC EFFECT ASSOCIATED WITH SELF-INDUCED

PHOSPHENES

On several occasions the author has preferred to undergo minor surgery without local anesthetic and to rely instead on autohypnotic analgesia-for example during extraction of an infected abscess from the back during laser surgery to

remove keloids and during the filllng of dental caries His experience on a recent occasion when a dentist had to abrade the surface of six teeth with damaged enamel in order to create a strong bonding surface are worth describing here because the experience implies that spindle waves can be induced even during a state of high physiological arousal For this appointshyment the author arrived in the office too late to hypnotize himself in advance

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 121

so he had to begin the normal induction procedures after the dental work was already underway

A s the dentist worked on the first tooth the author experienced apprehension sharp sensations of pain and an involuntary tensing of the large muscles of the body with each application of the drill As

the author kept his eyes converged and his attention focused on the center of the visual field the involuntary tensing in response to pain alternated with a precipitous relaxing of those same muscles immediately after the stimulus With the repeated relaxation came a sense of relief and of letting go that amelioshyrated the pain The pain-driven relaxation was much stronger than the relaxation that normally accompanies the authors self-induction of phosphenes and the alternation of a pain-driven tensing on one hand and the distancing effect of focusing attention on the visual field on the other hand resulted in a rapid dissociation from all external and internal stimuli including a signifishycant amelioration of painful sensations

Most striking is the fact that by the time the dentist reached the third toothshyafter only a few minutes of this pain-driven self-hypnosis-the author saw a normal sequence of 4 receding annuli followed by swirling clouds of amorphous expanding phosphene even though the dentist was still using the drill contemporaneously This experience suggests that thalamic sleep rhythms can be voluntarily induced even when the subjects level of physiological arousal is high

SIMILARITIES WITH ATTENTION-INDUCED PHOSPHENES

REpORTED BY OTHER OBSERVERS

Taxonomies of phosphene images always include examples of simple geometric phosphenes with circular or semi-circular shapes (disks annuli or crescents) as

14well as formless phosphene mists 11 - There are also a number of anecdotal accounts that are relevant for example Friedman an opthamologist who studied entoptic images by introspection describes a similar sequence of annuli induced by sustained inward concentration Circular waves of blue color may be seen in the dark by the dark adapted retina They start at the

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 122

periphery and move inward toward the macula as a concentrically contracting solid circle disappear at the macula and begin again at the peripheryl)

A valuable but often-neglected resource of information about phosphene imagery is presented in the literature of religious mysticism Many mystics reported having seen translucent colored lights while absorbed in prayer or meditation A list of descriptions excerpted from self-reports is presented in Table 1 (These excerpts are representative of phosphene images that appear during states of calm and inward-oriented concentration they do not include images associated with paroxysmal raptures) These phosphene images exhibit a relatively limited set of shapes and colors the shapes are either circular (eg rings disks wheels suns) or formless (eg mists snow smoke) and the colors are usually a variant of either green or blue The phosphene visions of mystics display shapes and colors that are comparable to the images described by the author this and the many similarities in the behaviors used to induce phosphenes suggest that both sets of phosphenes have a common etiology

DISCUSSION

Whether the author uses self-hypnosis to induce phosphenes or experishyences them as hypnagogic images the threshold sequence of receding annuli has the same characteristics In both these

instances the antecedent behaviors involve a state of low physiological arousal combined with mental withdrawal from external stimuli These parallels suggest the hypothesis that phosphene displays are related to sleep-wake transitions

PART I RECEDING ANNULI AND THALAMIC SPINDLES

Mechanisms controlling the transition from waking to NREMS Based on the work of several research teams16-20 a consensus scenario for the generation of NREMS has emerged In this scenario NREMS is the product of three brain rhythms that interact with each other in thalamocorticothalamic circuits During the drowsy transition to sleep which in humans is called stage l NREMS the low voltage activity in the cortical electroencephalograph (EEG) still shows a pattern of intermittent desynchronization The polarization of

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 123

Table I Excerpts from self-reports of light visions by religious mystics

HEBREW MYSTICS the appearance of the wheels was like the gleaming of beryl and the four had the same form

their construction being something like a wheel within a wheel Ezekiel like a dome shining like crystal spread out about their heads And above the dome something

like a rhrone in appearance like sapphire Ezekiel a round Iodder like a full sphere rolling back and forth before him bright blue R Abulafia A glowing light clear brilliance A purple light that absorbs all lights R Moses de Leon

HINDU AND BUDDHIST MYSTICS a perfectly round beautiful deep-blue shape of a size appropriate to the center of a mandala as

if exquisitely painted of extreme c14rity Tsong Khapa a luminous revolving disc studded with lights a lotus flower in full bloom Gopi Krishna both my eyes became cemered When this happened a blue light arose in my eyes like

a candle flame without a wick and stood motionless in the ajna chakra S Muktananda

MUSLIM MYSTICS [like] chandelierssublime lights [like] stars moon or the sun Sharafuddin aI-Maneri its color is deep blue it seems to be an upsurge like water foom a spring Najmoddin Kobra visualize yourself as lying at the bottom of a well [looking up at the light of the opening] and

the well in lively downward movement Najmoddin Kobra the color green is the suprasensory uniting all the suprasensories Alaoddawleh Semnani the light rises in the Sky of the hean taking the form of light-gilling moons Najm Razi

CHRISTIAN MYSTICS his own state at prayer resembles a sapphire it is as clear and bright as the sky Evagrius descending like a bright cloud of mist like a sun round as a circle Simeon Neotheologos saw something in the air near him He did not understand the rype of thing but in some ways

it appeared to have the form of a serpent with many things that shone like eyes although they were not eyes Ignatius of Loyola

the soul puts on a green amilia [cape worn on shoulders beneath armor] John of the Cross [the almilla is like a helmet which] coverS all the senses of the head of the soul It has one

hole rhrough which the eyes may look upwards John of the Cross a round thing about rhe size of a rixdaier all bright and clear with light like a crystal H Hayen I saw a bright light and in this light the figure of a man the color of sapphireblazing with a

gentle glowing fire the three were in one light Hildegard von Bingen saw a b14zing fire incomprehensible inextinguishable with a flame in it the color of the sky

Hildegard von Bingen saw placed beneath her fuet the whole machine of the world as if it were a wheel She saw herself phced

above it her eyes of contemplation magnetized towards the incomprehensible Beatrice of Nazareth I saw the eyes I do not know if I was asleep or awake Angela of Foligno kind of sunlit winged being like a childs head beneath two little wings Abbess Thaisia laquobullbull round patterns small circles would expand and eventually dissipate only to be followed by other small

circles of light Philip St Romain an extraordinary circle of gold light pulsating against a deep violet background There were

always four or fille As soon as one would fode another would appear Philip St Romain

middotItalics added to mark words referring to (l) rings appearing in sets of four (2) amorphous shapes such as clouds or flames (3) circular or eye-like shapes (4) colors from the center of the visible spectrum (gold yellow yellow-green green bluish green) and (5) colors from the lower end of rhe visible spectrum (blue purple violet)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 124

cell membranes (Vm) has already begun to drop (hyperpolarize) in the thalamic reticular nucleus (RTN) a thin sheath of GABAnergic inhibitory neurons that acts as a pacemaker When the Vm of RTN cell membranes drops to approximately V m -60 millivolts (mV) RTN cells stop firing single spikes which are associated with waking states and instead begin firing highshyamplitude 7-14 Hertz (Hz) spike-bursts These bursts wax and wane over 1 to 3 seconds-hence the name spindle -and recur at 3 to 10 seconds Spindle volleys are relayed across the cortical mantle by thalamocortical (TC) sensory relay cells In human studies the primary criterion for onset of the first fullyshyestablished episode of NREMS or stage 2 sleep is the presence of globalized spindles in the cortical EEG

When spindle bursts from the RTN stimulate TC cells to fire in synchrony this synchronous bursting pattern overwhelms the normal capacity of TC cells to relay afferent sensory signals The loss of consciousness at the onset of stage 2 NREMS is thought to be caused by this blocking effect 21

While the RTN is firing spindle bursts through the thalamus another process is activated in the cortex large numbers of cells across the cortical mantle begin to oscillate at a very low frequency laquo 1 Hz)

The cortical slow rhythm referred back to the thalamus via corticothalamic circuits intensifies the hyperpolarizing effect of the RTN spindle bursts on TC cell membranes When V m -75 mV the TC cells begin to generate their own intrinsic calcium currents which further increases hyperpolarization At V m -90 mV the RTN neurons stop firing spindle bursts The TC cells continue to fire low-threshold calcium spikes in patterns which are controlled by the cortical slow rhythm The interaction of these two oscillations generates the delta waves (1 to 4 Hz) which are associated with stage 2 NREMS

In a study of sleep rhythms using the cortical EEG Uchida Atsumi and Kojima found that the mean number of spindles required to induce delta wave activity (that is to induce Vm = -90 mY) is 478 plusmn 162 spindles (from 3 to 7 spindles)22 The mean number of spindles in a volley remains the same for a single individual over multiple trials

Based on the consensus scenario for generation of NREMS we can predict that a phosphene image generated as an epiphenomenon of a thalamic spindle

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 125

Table II Dara show rhe degree of correspondance berween rhe pulse panerns of rhalamic spindles based on intracellular research and rhe sparioremporal panerns of receding annuli phosphenes induced by rhe author using a rechnique of self-hypnosis

Receding annuli phosphenes Thalamic spindle bursrs

Mean number of signals 4 annuli 487 (plusmn 16) bursrs

Sparial exrension vs Thin band 1 - 3 seconds durarion of signal ( 05 -15 cm)

Periodicity of signals 5 seconds 3 - 10 seconds

Simultaneity in LGNs Yes Yes

Point of entry Peripheral VF Ventral amp lareral LGN

Trajecrory Bilareral concentric Unknown

Rare of flow Cons rant rare Unknown

Signal-ro-noise rario High High (shorr bursrs) (sharp brighr discrere)

Termination of sequence Mrer 4 signals Mrer 487 (plusmn 16) signals

will present the following characteristics (1) a high-definition burst-like signal (2) that recurs within 3 to 10 seconds (3) that follows a trajectory compatible with having entered the LGN from the RTN (4) that has a predictable mean for the individual subject and a range that falls somewhere between 2 to 7 annuli and (5) that the spindles will terminate automatically

The temporal patterns of receding annuli and thalamic spindle bursts are similar Table II illustrates the close match between the timing of receding annuli phosphenes and thalamic spindle bursts The most striking similarities are the mean number of signals required to induce termination (4 annuli versus 487 spindles) and the interval between signals (5 seconds for annuli versus 3shyto-lO seconds for spindle bursts) Neither alpha theta nor beta waves present this kind of stereotyped temporal pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 126

T he spatial features of receding annuli are functions of geniculate anatomy A spindle burst moving through the LGN to the cortex will acquire certain distinctive spatiotemporal characteristics because of the

unique curvilinear and laminar anatomy of the LGN A drawing of a macaque LGN based on a clay model constructed by Le Gros Clark23 is shown in Figure 3 The primate LGN is composed of six sheets of cells or laminae that fold over a central hylus In macaques the hylus rises steeply as it extends rostrocausally forming a high arch at the posterior pole in humans the hylus is much more shallow but the functional anatomy is thought to be essentially

23 24the same in both cases - The geometry of the arch forces each lamina to bend so as to constitute in effect one-half of a conical surface and each lamina with its hemi-conical shape contains visual relay cells representing the contralatshyeral half of the visual field (VF) Operating as a pair the complementary hemishycones of the right and left LGN form the functional equivalent of a single conical surface which represents the entire VE This conical geometry of the paired LGNs means a burst of otherwise formless excitation will acquire a distinctive shape as it propagates through the laminae of the LGN Imagine a horizontal section moving along the surface of a cone from base to apex that moving section forms an annulus that shrinks in diameter as it approaches the apex but retains its annular symmetry throughout its trajectory

Figure 3 also includes drawings that show how Connolly and Van Essen24

converted the 3-dimensional structure of lamina 6 the largest and most dorsal layer into a 2-dimensional map Connolly and Van Essen used data obtained by Malpelli and Baker25 to superimpose a grid that specifies the areas in lamina 6 that contain TC cells representing various degrees of isoeccentricity in the VE We will use this map at a later point to show how the movement of a spindle wave through a pair of LGNs correlates with what appears in the VE

The location of the RTN relative to the LGN is also shown in Figure 3 The RTN spindle pacemaker is a thin sheath of GABAnergic inhibitory cells that extends along the surface of the whole posterior ventral thalamus not just the LGN This extension brings the RTN into close proximity with the portion of the LGN (lateral wing) that protrudes out from the main body of the thalamus Some of RTN wraps around and beneath the ventral edges of the LGN26 The RTN comes closest to the LGN in two areas along the ventral edges of the longest laminae (lamina 6 and 1) and along the edge of the lateral

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 127

DORSAL POLE DORSALPOIEA B

L1 L4 L3 L

DORSAL POlE DORSAL POIE (FOVEA)

G LATERAL WING

25

DORSAL POL (FOVEA)

10 _DIAL

20 WING

~

wing These areas contain TC cells that represent the far periphery of the VE If a spindle burst enters the LGN at locations where laminae are in closest proximity to the RTN-along the ventral edges-then the discharge of TC cells will begin in the most ventral portions of the laminae the regions that represent the far periphery of the VE This matches the phosphene sequence observed by the author

Our hypothesis about how this proximity between RTN and LGN affects the trajectory of spindle waves is illustrated in Figure 4 We propose that it is not possible for the author to observe a thin annulus of phosphene sweeping in from all 3600 of the peripheral VF unless spindle bursts exhibit the following

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 128

Figure 3 [facing page Drawings of primate geniculate anatomy and functional anatomy relevant to the generation ofphosphenes (A) Anterior view ofa macaque monkey LGN based on a clay model reconstruction by Le Gros Clark 23 (B) Posterior view ofthe same model showing 6 laminae folded over a central hylus to form lateral and medial wings with the hylus arching steeply upward near the posterior pole to shape the laminae into layers of hollow half-cones nested together Note that the lateral wing of the LGN is slightly larger than the medial wing so that in situ the lateral wing protrudes out from the main body of the thalamus creating a small knob visible during dissection 26 (C) Schematic drawing of an oblique section through median axis (also adapted from Le Gros Clark13 showing how the laminae fuse together at the anterior pole The afferent ganglion cell axons that form the optic tract (OT) penetrate through the anterior surface to reach their target relay cells in the laminae (D) Drawing of the most dorsal lamina-layer 6--separated from the rest of the LGN The geometric shape is a hollow half-cone so that right and left LGNs placed back-to-back form in effect a single cone Note also the position ofthe RTN shown here as a striped bar relative to lamina 6 The position of the striped bar shows that the RTN makes direct contact with lamina 6 at the edge ofthe lateral wing and also along the ventral edges (E - F) Schematic drawings adapted from Connolly and Van Essen24 that show how a 3-dimensional lamina-lamina 6--can be transformed into a 2-dimensional triangular figure lamina 6 is removed and its wings unfolded (E) creating a slightly asymmetric triangular figure (F) which is adjusted to an oblong shape (G) in order to superimshypose a grid matrix with minimal distortion The grid plots locations of TC cells that represent various isoelevations and isoazimuths in the VF locations derived from the experimental observations published by Malpeli and Baker 25 Note the relatively large amounts of laminar surface allocated to central vision (0 0

- 30 0) as compared

to peripheral vision (30 0 - 80 0)

characteristics (1) Spindle bursts must move simultaneously through both geniculate nuclei This pattern of movement is consistent with anatomical studies in primates that found axonal projections linking the right and left RTNs27-28 and with experimental studies in cats that found spindles appearing simultaneously in both right and left thalami 29 (2) Spindle waves must enter the ventral edges of the LGN first and move ventrodorsally in a highly coherent pattern-moving in effect as a standing wave This pattern of movement is consistent with in vitro experiments using sagittal slices from a ferret LGN where spindle waves originated spontaneously at the edge of a slice in an area which contains cells that represent peripheral vision then propagated toward that area of the slice containing cells that represent central vision in the ferret 3o

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 129

VF

PG BIlateral receptive lleJd of PVN YI(j Inward dmKooflality Adapled

0-- from Mortgr at at (1987)

V1

ibull t bull

RTN t t t t t t 1middot3 SECOlO BURSTS OF 7middot14 HZ SPiKES RECURRNG EVERY 3 10 SECONDS

To our knowledge the LGN is the only anatomical structure in the visual system that has the capacity of passively forcing a wave of excitation to flow across a conical surface thereby generating the sensation of a phosphene annulus that retains its symmetry as it shrinks in diameter The retina has a circular anatomy but it is not likely that the mechanical deformation of the retina would produce a wave that began simultaneously in all 3600 of the retinal rim nor that the symmetry of annular wave would be preserved as it flows inward toward the foveal region

The hypothesis presented here-that there is a structure in the visual system that imprints a conical shape on standing waves that move through it-explains

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 130

Figure 4 facing page Schematic drawing of contemporaneous events in selected regions of the visual processing hierarchy (A) The left and right RTNs fire spindle bursts simultaneously (B) The bursts pass through the right and left geniculate laminae as standing waves of depolarization entering from the ventral edges and moving ventrodorsally in parallel In order for the phosphene annulus to appear to be flowing at a constant rate the spindle wave flowing through the LCN must expand in width as it ascends ventrodorsally so that by the time the fill-in disk appears-when the center 30deg of the VF is covered by the phosphene annulus-the spindle wave must have expanded enough to activate relay cells in the most dorsal 50 of lamina 6 (C) Signals representing two complementary hemi-annuli are kept separate in the primary visual cortices (area VI) (D) Signals representing the two hemi-annuli are integrated into signals of a single annulus when they reach area PC in the posterior parietal cortex where the receptive fields of single parietal visual neurons have the capacity to register bilateral signals that exhibit opponent vector movement (that is signals converging from opposite directions along the central axes-as if an object were moving away from the viewer)46 Neurons in area PC also integrate wavelength (color) signals from the extrastriate visual pathway with signals about brightness motion and depth from the parietal visual pathway to compose a representation of an object in space-in this case of an annulus that appears to recede 32

the authors experience during MRI when he observed a continuous succession of receding annuli every 2 seconds in this view the energy of the electroshymagnetic bombardment when released during precessional relaxation flows through the geniculate laminae in the same way that the RTN spindle bursts do that is as a standing wave and thus the visual epiphenomenon is the same in both cases if the subject keeps the eyes focused straight ahead and the attention fixated In a study of phosphenes evoked by electricity in conjunction with hallucinogenic drugs Knoll Kugler Hofer and Lawder found that each subject sees specific kinds of phosphene at different frequencies and that these frequency-specific images are stable enough to be reproduced after six months31

They conclude that the tunability of the electrical stimulation frequenshycies within the EEG range to various definable phosphenes requires the existence of a resonance system One mechanism contributing to that resonance system may be the functional anatomy of the LGN

The colors of receding annuli as functions of geniculate laminar anatomy The colors of receding annuli phosphenes are consistent with the patterns of discharge spindle waves can be expected to stimulate as they move through

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 131

geniculate laminae As shown in Figure 5 the six laminae differ (1) in the types of wavelength signals relayed (2) in physical size and (3) in the area of the VF represented 24-25 Only 4 out of 6 laminae Cparvocellular layers 3shy6) contain TC cells that relay wavelength signals the other 2 laminae (magnocellular layers 1 and 2) do not encode wavelength Among parvocelshylular laminae only lamina 6 the longest and most dorsal layer contains TC cells that can represent the far periphery of the VF (from 800 to 50deg of isoeccenshytdeity) therefore when the spindle wave enters the peripheral VF only those wavelengths relayed by lamina 6 will participate in composing a cortical lightness record (See Zeki)32

I n lamina 6 ganglion cell axons arriving from the retina carry two kinds of wavelength signals (1) center-ON signals from medium-wavelength cones (M-cone center-ON) and long-wavelength cones (L-cone centershy

ON)33-35 Using the cone spectral sensitivity curves (adapted from Marks et al 36) we average the wavelengths that elicit maximal responses for M-cones (535 nanometers) and L-cones (520 nm) which yields a mean wavelength value of 550 nm In humans this wavelength generates a sensation of green or yellowshygreen the sensation observed by the author

As the spindle burst moves ventrodorsally it reaches the dorsal areas in the geniculate laminae which contain TC cells representing the central 0deg to 20deg of isoeccentrieity in the VE All 4 parvocellular laminae have TC cells which are potentially capable of representing this central region of vision but the authors observation that the color of the filling-in disk changed from green to blue implies that in the early years of phosphene induction the spindle wave must have remained close to the surface of the LGN stimulating only laminae 5 and 6 which generates a sensation of yellow-green When the fill-in disk was observed to change color from green to blue the spindle wave must have been rechanneled so that it began to penetrate below laminae 5 and 6 and to activate laminae 3 and 4 the only laminae that relay blue-sensitive signals (Sshycone center-ON signals)3 In light of the authors MRI experience it seems likely that a spindle wave requires a minimum of 2 seconds to reach the blueshysensitive cells of laminae 4 therefore during MRI when the receding annuli disappeared after 2 seconds half the normal duration the fill-disk had a green color even though it had long since change to blue in other induction settings with a 4-second trajectory

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 132

A REPRESENTATION OF THE VISUAL FIELD IN EACH LAMINA

orooqUtftc O-u OCIJ1SALfIOLI (I01flAj

0

10

20

30

40 n50 Of

60

70

20 loO 1Mgr_ II~ o UIpoundAS65 mn1MY-o actlvncL ~~~r

Jll-COMcetlImiddot~

II LAYERSU 3 GatQYancetl~ (1) ucon ceom-oyenF (2)l~cen()FF 3) ~ cenloH

II~ cng1loqctWIIIfNla

iICINe -- (t81Otdb1t1d~OH (2)~

80

B CONE SPECTRAL SENSITIVITY CURVES

S-COHS

WAVIlLllNG1llS OF UGHT IH NANOMllTERS (NM)

Figure 5 Phosphene color as a function of ganglion cell distribution in parvocellular laminae (Aj Schematic drawing ofthe proportion ofthe VF represented in each laminae The proportions shown here are based on the work of Connolly and Van Essen24 The

far periphery of vision (50 0 to 80 0 of isoeccentricity) is represented in only two laminae-laminae 1 and 6-and of these two only lamina 6 is a parvocelLular lamina capable ofencoding wavelength signals Therefore only those wavelengths relayed by lamina 6 will participate in forming a cortical lighmess record for the far periphery of the VP (B) Cone spectral sensitivity curves (adapted from Marks et al)36 Using these cone sensitivity curves we can estimate the sensation stimulated by a spindle wave moving through lamina 6 by averaging the wavelengths that elicit maximal responses for M-cones (535 nanomeshyters) and L-cones (520 nm) which yields a mean wavelength value of550 nm In humans this generates a sensation of green or yellow-green the sensation observed by the author when the receding annulus enters at the far periphery of the VP For a calculation of the cortical lightness record when a spindle wave moves through 20deg to 0deg ofthe VF stimulating all 4 parvocelfular laminae see the text and Figure 6

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 133

Once the spindle wave penetrates to laminae 3 and 4 it may activate all 4 parvocellular laminae stimulating TC cells to send contradictory wavelength signals for the same retinotopic location the signals sent from laminae 4 and 3 will encode blue light (S-cone center-ON plus M-cone center-OFF and Lshycone center-OFF) while the signals sent from laminae 5 and 6 encode yellowshygreen light (M-cone center-ON plus L-cone center-ON) This kind of contrashydiction does not occur in normal retina-based perception where light energy striking the retina is structured by the retinas center-surround and colorshyopponent organization to encode only one set of wavelength signals for each spatial locus 32 In Figure 6 we estimate the cortical lightness record that results when contradictory wavelength signals compete to be represented in consciousshyness Our calculations suggest that the outcome will be a mean wavelength which in humans elicits a dark blue or violet sensation

PART II AMORPHOUS PHOSPHENES amp THALAMIC DELTA ACTMTY

M echanisms controlling the transition from spindle bursts to delta activity In the consensus scenario for the generation of NREMS16-20 we noted that the RTN shifts to firing spindle bursts

when polarization of thalamic cell membranes drops to V m = - 60 mV At the same time cortical cells begin oscillating with a synchronous slow rhythm laquo 1 Hz) Both processes further decrease the Vm of TC cell membranes When Vm = - 75 mY TC cells begin to generate their own intrinsic calcium currents which also decreases V m At V m = - 90 mV RTN neurons stop firing spindle bursts At the same time the TC cells begin firing low-threshold calcium spikes in alternation with after-hyperpolarizations (LTS-AHP) Because sensory relay neurons in the LGN are not linked to one another by locally projecting axons the firing of one TC cell does not excite its neighbor However a lack of local connectivity does not mean that TC cells occupying the same laminae release their AHP-LTS calcium spikes in a random distribshyution rather spikes are released simultaneously by groups of cells in synchrony with the advent of the cortical slow wave In effect the distribution of LTSshyAHP spikes firing in the LGN is determined by the spatial propagation of the cortical slow wave Thus the delta wave (1 to 4 Hz) activity detected by cortical EEG during NREMS is a product of the interaction between the AHP-LTS calcium spikes released by TC cells and the cortical slow rhythm

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 134

CORTICAL PROCESSING OF CONTRADICTORY

WAVELENGTH SIGNALS

KEY _ Cells firing

cJ Cononol firing

Assume that as a spind6e wave moves through the LGNlt fires simultaneously aU the TC cells that represent a particular reUnoshytopic locus (x y) in each of the six laminae As a result cortical cells engaged In the higher level processing of visual signals will receive more wavelength signals representing retina locus (x y) than are generated by normal perception laquo and some of these afferent wavelength signals may contradict other signals arriving simultaneously

CORTICAL LIGHTNESS RECORD SlgnalSell

Intemal contradictions not congruent wilt pre

SmiddotON eristing neuron neta

s bullbull M-ON LmiddotON

3 bullbull M-OFF + L-OFF

a-ON 12

ROD-ON

No Internal eonlradlemiddot

--------1I =~8b~~~~~~~t signals

3+4

~ --OFF Excludes 6 Of 7 $J9n18

1+2 B-ON I

IWmiddotHmiddotI Signal Sell

1111111 No Intern1 conlrfldlcshy lion

Exelvdta 4 out of 7 efshy

bullbullbull bullbullbull ferant signals

No Intern1 contradic_ tionnee S-ON BshyOH and ROO-ON can all be coacllve at low lImlnance levels nef Ihe rod-eone break

ExchJde$ only 2 Ollt of 7 afferent signals

Figure 6 Selection of competing wavelength signals based on neuronal group selection This thought experiment is based on Edelman sconcept ofneuronal group selection 73 We assume that all possible combinations ofsignals will form sets and that all signal-sets will compete to make the most efficient match with pre-existing neuromd networks that have been forged over years ofnorma reti1U1-based perception We also assume that pre-existing neural networks are most likely to expedite those sets that satisfY 2 criteriI (J) the signals in a set do not contradict each other and (2) fower signals are excluded than in the other sets that satisfY the first criterion In our analysis Set 4 wins the competition because it does not contain internal contradictions and excludes fower signals (2 out of 7) than Set 3 excludes (4 out of7) It is not an internal contradiction that Set 4 contains both rods and cone Signtlls in normal retina-based perception when luminance levels approach the rod-cone break S-cone center-ON receptors send signas as do rod receptors and there is even evidence that rod activity may actually drive S-cone activity even after luminance levels foIl below the rod-cone break74 To calculate the cortical lightness record for Set 4 we average the wavelength that elicits maximal responses foom rods (511 nm) and for Sshycones (430 nm) which yields a mean wavelength of 470 nm which in humans results in a dark-blue or violet sensation

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 135

The cortical slow rhythm is an example of a generic pattern of neuronal excitashytion that occurs in large networks of neurons linked by local projections A recent experiment by Maeda Robinson and Kwana38 shows that networks of locally-connected neurons spontaneously generate periodic synchronized bursts of calcium transients that propagate across the network in an expanding spatial wave a pattern that represents a stable mode of firing towards which these neuronal networks relax following perturbations for example by electronic stimulation or by drugs Understanding the characteristics of these waves is an important prerequisite to understanding the mechanisms that produce the amorphous phosphene images as a visual epiphenomenon

To study the spontaneous periodic synchronized bursts the researchers prepared cultures of dissociated cortical neurons and allowed them to mature for several days in vitro (DIV) After 3 to 4 DIV when concenshy

trations of extracellular magnesium were low electrodes began to detect spontaneous synchronized bursts of low frequency calcium transients (between 01 and 1 Hz) that originated in different locations on the sheet every 10 to 20 seconds and spread across the sheet of cells at a relatively slow speed averaging 50 mmsecond The researchers could not predict where a wave would originate or where it would expand rather the initiation and expansion of waves was generated by spatial and temporal summation of a continuous random background of synaptic inputs including miniature spontaneous synaptic events but the pattern was not random since waves propagated sequentially from electrode to electrode as each local group of neurons charges up its neighboring nontefractory areas rather than in a random sequence of regions38

The excitability of the cells in the sheet determines the probability first that there will be a synchronous burst and second that it will spread in a particshyular direction Cells become more excitable as the cultures mature which means the refractory intervals between successive bursts were much shorter in mature cultures (gt 30 DIV) than in early cultures laquo 7 DIV) Some cells became so insensitive to inhibition that they continued to fire bursts even when extracellular concentrations of magnesium were relatively high Finally there were refractory periods of 5 to 10 seconds during which no bursts occurred even when an electrical stimulus was applied This refractory interval for cultured networks is slightly longer than the refractory interval observed of the cortical slow wave in vivo which 25 to 4 seconds 18- 19

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 136

Based on the observations about cortical slow waves we can predict that phosphenes generated as epiphenomena of delta wave activity will present the following signal characteristics (1) signals that appear at unpredictable locations in the VF (2) signals that expand and diverge asymmetrically following unpredictable trajectories which may encompass large areas of the VF (3) signals that move relatively slowly (50 mmsec) (4) signals that recur with a period of 2 to 4 seconds reflecting entrainment by the cortical slow wave (5) signals that do not terminate automatically after a predictable number of cycles

The spatial patterns of phosphene mists and thalamic delta waves are similar The spatiotemporal characteristics of amorphous phosphenes match the pattern of wave propagation associated with periodic spontashy

neous synchronized bursts in large neuron networks the amorphous phosphenes enter the visual field at unpredictable locations expand and diverge asymmetrically with a slow steady rate of flow follow trajectories that are unpredictable and exhibit a refractory interval The amorphous mists do appear to have a periodicity although the author is unable to sustain the vision while also counting the seconds therefore he is unable to determine if it compares to the period of the cortical slow wave (25 to 4 seconds) but his impression is that it feels roughly the same as as with receding annuli which recur at 5 seconds Also the refractory interval feels as if it decreases as the induction session is extended These similarities suggest that the amorphous phosphenes are generated by stage 2 NREMS delta wave activity which is an activity governed by the reverberation of the cortical slow wave in thalamoshycorticothalamic circuits The cortical slow wave is referred to the LGN where it modulates the firing of visual relay cells in the laminae and since relay cells do not have local dendritic connections the expansion of a wave of depolarshyizations moving from one relay cell to the next across in the laminar surface will mirror at least in part the expansion of the cortical wave that is spreading contemporaneously through locally-connected cortical cells

PART III RETENTION OF CONSCIOUSNESS

In a normal transition to NREMS the volley of synchronous spindle bursts that marks the onset of stage 2 NREMS overwhelms the normal firing pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 137

of thalamocortical cells preventing their relay of afferent sensory signals and inducing a loss of consciousness21 But the loss of consciousness cannot be timed precisely using cortical EEG the thalamus is too remote for the onset of spindling to be reliably detected by scalp electrodes39 In experiments with cats where electrodes could be implanted in the thalamus researchers found that spindling often reached peak levels of activity in the thalamus-a level of activity consonant with stage 2 NREMS-at a time when the cortical EEG was still showing intermittent desynchronizations a pattern characteristic of the drowsy stage 1 transition not a fully-established stage 2 NREMS episode4o

In other words there is a short period of time in which the synchronous rhythms of stage 2 NREMS are installed in the thalamus but not in the cortex where cortical neurons continue to depolarize in response to afferent sensory signals

T his finding suggests a possible explanation for the authors ability to retain consciousness while spindle bursts are sweeping through the LGN if he is able to extend the duration of this time lag between

the onset of spindling in the thalamus and spindling in the cortex if he is able to stimulate the visual cortices in such a way that they continue to depolarize then he may be able to keep on processing visual signals-to remain visually aware-even after the non-visual thalamus and non-visual cortex become entrained by synchronous sleep rhythms The authors induction technique includes several behaviors which are known to enhance the responsiveness of visual neurons-eye movements attentive fixation and an attitude of expectancy

Effects of eye movements and attention on the LGN Sustained convergence causes periorbital proprioceptors to send excitatory feedback directly to the LGN41 Also convergence further enhances the excitability of geniculate cells by stimulating the superior collicus (SC) which sends its own excitatory signals to the LGN42-43 These signals from the SC are known to selectively enhance the excitability of visual relay cells that represent the periphery of vision44 We know in the authors case that the SC is being stimulated because he is able to keep on fixating an ability which would normally be lost during the transishytion to NREMS45 The ability to fixate can be retained however if the SC is stimulated (even if stimulated during NREMS)46

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 138

Effects of eye movement attention and expectancy on the primary visual cortex The PET study of mental imagery by Kosslyn et al 3 showed that even a baseline resting state of relaxed immobile expectancy can generate signifishycant increases in neuronal activity in the primary visual cortices Further increases can be induced by sustained eye movements

A sustained convergence will release a stream of ponto-geniculo-occipital (PGO) waves These PGO waves called eye movement potentials or EMPs last only as long as the eye movement1747 whereas the PGO waves associated with rapid-eye-movement sleep (REMS) fire continually for the duration of the REMS episode Both REMS-related PGO waves and EMPs have the same desynchronizing effect on the visual pathways they move through the LGN depolarizing the thalamocortical cells which relay the signals to cortical neurons The responsivity of neurons in the primary visual cortices is enhanced by the stimulation of PGO waves 1747-49 If the passage of EMPs causes the genicushylate relay cells and their cortical targets to depolarize regularly then a volley of 4 spindle bursts moving through the same pathways will register as just another series of depolarizations in effect the spindle bursts are processed by the visual system as if they were sensory signals sent from the retina rather than an event stimulated by endogenous mechanisms

T he impact of eye movements and ftxation on the parietal visual cortex Convergence and attentive fixation will also enhance the responsiveness of light-sensitive parietal visual neurons (PVNs) in area PG of the

posterior parietal cortex 50 In experiments where monkeys are trained to fix their attention on a screen-and to keep on fixating even if no targets appearshythe excitability of these light-sensitive PVNs increases by as much as 350 51

52-53Responsiveness is also facilitated by the angle of gaze Also area PG is the first region in the visual pathways containing individual neurons with the capacity to respond to large bilateral stimuli moving in opposite directions along the central meridians of vision (opponent vector motion) 853-55 Facilitation of PVNs in area PG has the effect of sensitizing the subject to bilateral opponent vector motion and this is especially true if the movement appears in the periphery of the VE 8

Intracortical ampliftcation and feedback to the LGN When PGO waves and signals from the SC arrive in the primary visual cortex they may be relatively weak however weak signals can be amplified by reverberating in large networks

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 139

of cortical cells linked by local projection 56 There are nine times as many excitatory links among cortical cells as there are projections from the visual cortex to the LGN an imbalance which suggests leads Suarez Koch and Douglas to propose that geniculate input provides only a minor fraction of the excitatory input the majority originating in neighboring and recurrently connected cortical cells57 If the excitabiliry of cortical neurons is slightly higher than normal then this process of amplification may continue even after the LGN signals that initiated the reverberation are no longer being transmitted by the LGN ( a hysteretic mode of operation) 57

Feedback from hyperexcited cortical neurons will stream back to the LGN via corticogeniculate projections which outnumber geniculocortical projections ten-to-one One effect of this feedback is that the LGN is

able to absorb large amounts of information flowing back from the cortex 58

As signals reverberate back and forth in thalamocorticothalamic circuits a matching process takes place those geniculate relay cells that fire in patterns consistent with the firing patterns of active cortical cells will have their responshysivity enhanced while those geniculate cells that fire in patterns not consistent with cortical cells will be suppressed 59

Preservation of consciousness by selective facilitation of the visual pathways By combining all of the facilitatory effects produced by the authors eye movements and attentive fixation-(l) stimulation of the LGN by feedback from periorbital proprioception both directly and indirectly via the SC (2) the release of PGO waves (EMPs) that facilitate neurons in the LGN and primary visual cortex as they pass (3) the facilitation of the primary visual cortex by a state of relaxed immobile expectancy (4) attentive fixation and angle of gaze that facilitate PVNs in area PG (5) intracortical amplification of signals received from the LGN and (6) corticogeniculate feedback that stimulates the LGN-we delineate a circuit of enhanced excitability that extends from the LGN through the post-geniculate visual heirarchy to area PG where signals are integrated into representations of objects

The hyperexcitability of neurons all along the post-geniculate visual pathways creates conditions in the visual cortices which are similar to those present during EEG-desynchronized states of waking and REMS Therefore neurons in the visual pathways are too excitable to be entrained by synchronous bursting

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 140

patterns when spindle waves move through them instead the spindle bursts stimulate visual neurons to depolarize and then recover as happens in response to afferent sensory signals during waking states It is important to note that for this to occur none of the constituent neuron assemblies is required to perform an abnormal operation the abnormality is a function of the authors intent to activate contemporaneously neuron assemblies that would not normally be co-activated

PART IV HYPNOTIC ANALGESIA

Manipulation of spatial attention as a method for alleviating pain sensations In a theoretical article on the neurophysiology of hypnosis Crawford and Gruzelier60 propose that variations in hypnotizability are function of variability in the efficiency of the frontolimbic (anterior) attentional system in humans high-hypnotizables are better able to sustain focused attention on a task and to ignore extraneous stimuli than are low-hypnotizables

I na related empirical study that compares the use of attention by subjects with high versus low hypnotizability Crawford Brown and Moon61 report that highly hypnotizable persons continue to show physiological reactivity

while cognitively not perceiving the painful stimuli Through disattentional processes they can dissociate themselves from the awareness of pain The authors phosphene induction behaviors-and the cutaneous analgesia he experishyences-appear to involve the same kind of behaviors that is a mobilization of frontolimbic attention used to withdraw attention from external stimuli and to concentrate it on internally-generated phosphene images This suggests the hypothesis that the mechanisms that generate phosphenes might also produce hypnotic analgesia There are several ways that visual signals and pain signals might interact to produce this analgesia

Competition between pain and vision signals for limbic registration The fully-developed sensation of pain requires integration of rwo kinds of informashytion Signals that encode the location and intensity of a noxious stimulus (nociceptive signals) are relayed via the thalamus to the somatosensory cortices which registers only the sensory-discriminative aspects of pain perception62 before reaching consciousness the nociceptive signals must be sent to the limbic

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 141

system where they are linked with signals from long-term memory that encode the affective significance the stimulus has acquired for that individual Studies of brain metabolism show this linking of somatosensory information with limbic associations takes place in the anterior cingulate (CG) and anterior insula62-64

PET studies also show that the anterior CG is activated when subjects shift their spatial attention in response to expectations as to where

66stimuli will next appear65- This is precisely what takes place during the state of immobile expectancy that induces phosphenes Since visual signals and nociceptive signals both require limbic enhancement which is only possible if they get access to the anterior CG there might be conditions in which the two types of afferent sensory signals have to compete for that access In a theoretical article on the mechanisms of attention Posner and Rothbart67

propose that visual signals can interfere with nociceptive signals by blocking access to the anterior CG As behavioral evidence they cite studies showing that when young infants make distress calls they can be distracted by the presentation of a new visual stimulus We have shown the evidence of such control at about three months Orienting to visual events can be employed to quiet or calm negative vocalizations However the distress appears to be maintained and reappears when the infants attention to the stimulus is reduced Caregivers also report the use or visual orienting to block overt manifestations of distress at about this age 67

The effects of disattention on the somatosensory cortices If there is a competition between visual signals and nociceptive signals for access to the anterior CG it is likely that the competition will be affected by the relative volume of signals received A recent study suggests that focusing attention on internally-generated visual stimuli may reduce the number of nociceptive signals relayed by the somatosensory cortices Drevets Burton Videen Snyder Simpson and Raichle68 have shown that the mere anticipation of a touch at a specific cutaneous site increases the flow of blood to those cortical somatosenshysory neurons that are linked with that site where touch is expected and decreases the flow of blood to neurons linked with sites where touch is not expected In this experiment the researchers designated touch as the behaviorally significant sensory stimulus but their findings suggest that the outcome could be reversed if the instructions were reversed if subjects were

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page J42

instructed to direct attention away from a cutaneous site where a noxious stimulus was being applied if they were instructed to relax close their eyes and concentrate on the play of phosphenes in the visual field as the behaviorally significant sensory stimulus then it would be reasonable to expect that the flow of blood would decrease to the somatosensory neurons linked with the cutaneous stimulus and that the flow of blood would increase to the visual cortices The decrease in blood flow to somatosensory neurons implies less neuronal activity which implies that fewer signals are being sent forward to the anterior CG than would have been sent if instead the subject were treating the touch as the behaviorally significant sensory stimulus If fewer pain signals arrive at the anterior it is reasonable to infer that the conscious experience of pain will be muted by the diversion of attention to internal visual stimuli

Differential impact of sleep rhythms in the visual and nonvisual thalamus There is another mechanism that might also contribute to the analgesic effect of inducing sleep rhythms PET studies show that

the thalamus is involved in the relay of nociceptive signals to the cortex63 although some confusion remains about which kinds of signals are relayed by which subregions in the thalamus62 One thalamic site clearly identified by anatomical studies as a relay for nociceptive signals is the ventroposterior lateral nucleus (VPL)69 If synchronous sleep rhythms are active in the thalamus we can reasonably expect that the VPL will itself be entrained by synchronous oscillations and that it will relay the sleep rhythms to somatosensory cortices Relay neurons in the VPL are not stimulated by feedback from eye movements and fixation as are relay neurons in the LGN which suggests that sleep rhythms may impede the relay of nociceptive signals via the VPL but not the relay of visual signals via the LGN

Brain waves associated with anesthesia and NREMS The hypothesis presented here-that consciousness can be preserved despite the presence of NREMS activity-is consistent with a recent report that the kinds of fast brain waves which are normally associated with conscious states are also present during NREMS and anesthesia two states which were thought to involve minimal brain activityJo Another recent study found that there is a close resemblance between the slow brain waves that appear during NREMS and those that appear during certain types of anesthesia71

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 143

bull bull bull

CONCLUSION

In this paper we have presented evidence supporting the hypothesis that phosphene images can be generated as an epiphenomena of thalamic spindle bursts and delta wave activity normally associated with NREMS The prereqshyuisites for inducing these sleep rhythm phosphenes are relaxed immobile expectancy sustained convergence and attentive fixation of an undifferentiated visual field Our hypothesis provides a necessary and sufficient explanation for the authors induction of phosphenes and perhaps also for the generation of phosphenes reported to appear spontaneously during the drowsy transition to sleep (hypnagogic states) during sensory deprivation or during certain kinds of prayer or meditation all of which involve a similar state of relaxed immobile expectancyJ2

CORRESPONDENCE Philip T Nicholson bull 52 Norfolk Road bull Chestnut Hill MA 02167

REFERENCES amp NOTES

1 M 1 Posner Modulation by Instruction Nature 373 (1995) pp 198-199 2 J Reissenweber E David amp M pfotenhauer Investigations of Psychological Aspects of

the Perception of Magnetophosphenes and Electrophosphenes Biomedizinische Tecknik 373 (1992) pp 42-45

3 S M Kosslyn W L Thompson 1 J Kim amp N M Alpert Topographical Representations of Mental Images in Primary Visual Cortex Nature 378 (I995) pp 496-498

4 P E Roland amp B Gulyas Visual Memory Visual Imagery and Visual Recognition of Large Field Patterns by the Human Brain Functional Anatomy by Positron Emission Tomography Cerebral Cortex 51 (1995) pp 79-93

5 H Benson The Relaxation Response (Morrow New York NY 1975) 6 ] H Schultz amp W Luthe Autogenic Training a Physiological Approach to Psychotherapy

(Grune amp Stratton New York NY 1969) 7 E Jacobson Progressive Relaxation (University of Chicago Press Chicago IL 1938) 8 M A Steinmetz BC Motter C] DuffY amp V B Mountcastle Functional Properties

of Parietal Visual Neurons Radial Organization of Directionalities Within the Visual Field Journal ofNeuroscience 71 (1987) pp 177-191

9 R R Edelman Magnetic Resonance Imaging of the Nervous System Discussions in Neuroscience 71 Elsevier Science Amsterdam (I990) also J H Newhouse amp ] I Wiener Understanding MRI 1st Ed (Little Brown Boston MA 1991)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 144

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

While the color of the annulus has remained the same over time the color of the filling-in disk changed after about two years of intermittent phosphene induction from yellow-green to blue The change began with tiny flecks of blue flashing amid the green just as the disk disappeared Over a period of several weeks the amount of blue expanded and appeared earlier in the fillshysequence Within a month the entire fill-disk was blue

The shrinking annuli create a psychological illusion of a ring of light receding toward a distant point in 3-dimensional space and pulling the attention into a vortex or paradoxically the same progression can create a sensation of falling backwards an illusory motion that resembles an effect produced by optic flow Motion in the visual periphery elicits in the stationary observer an illusion of self-motion (vection) indistinguishable from real motion The illusion of vection is compelling for it dominates contradictory proprioceptive signals For example subjects presented with optic flow consistent with backward self-motion perceive backward motion even if they ate actually walking forward 8

T he same receding annuli appear spontaneously as hypnagogic images while the author is reclining and waiting for sleep The receding annuli appear whenever the authors mind and body are relaxed his eyes closed

and his attention focused straight ahead-essentially the same behaviors used for self-hypnosis-but in the hypnagogic context virtually no effort is required the receding annuli feel as if they were released spontaneously not induced If the author is not relaxed or if he is distracted by a headache or importuning thoughts then the luminous receding annuli do not appear Instead the author loses consciousness abruptly at the onset of NREMS

AMORPHOUS EXPANDING PHOSPHENES

(A) loCAL RANDOMLY-DISPERSED EXPANDING WAVES Figure 2(A) illustrates one kind of amorphous phosphene mist that appears after the receding annuli sequence terminates These phosphenes are small amorphous swirls of yellowshygreen that coalesce suddenly at unpredictable locations in the VF and expand for a second or two then fade into the background There are often several images drifting in the visual field at the same time each in a different stage of evolution and the density of the phosphene seems to vary with some areas appearing thin and translucent others more opaque-like puffs of smoke that

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 117

10 seconds 15 sec 20 sec

25 Bee 30 sec 35 sec

expand and curl aimlessly then dissipate Because these waves are so unpredictable and formless the author is unable to predict the mean number of signals per episode the period between signals the site of entry or exit or to define a typical trajectory other than in the abstract generic manner used above The signal-to-noise ratio in these phosphenes is very low since phosphene stands out against the background there clearly is a signal but this signal presents so little pattern that it is essentially a form of phosphene noise These localized pulsations may continue for several minutes but usually within a minute or two they are superceded by the type of amorphous wave described next

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 118

Figure 2 [focing page Schematic drawings of of amorphous expanding phosphenes (A) Brief randomly-dispersed localized pulses These phosphenes are the first to appear after the receding annuli They coalesce at unpredictable locations in the IF expand asymmetrically for a second or two then dissipate into eigengrau before there is time to extend very for beyond their locus of origin (B) Periodic unidirectional amorphous expanding waves These phosphene waves enter the periphery ofvision from one hemifield presenting as a loosely-defined crescent (hemi-annular) cloud that mirrors the curvature of the peripheral rim The leading edge of the wave expands and flows across the vertical meridian into the opposite hemified swirling around the periphery curling inward and merging while at the same time the trailing edge ofphosphene dissipates rapidly in those regions over which the wave has already passed like mist or smoke evaporating in air The author is unable to time these waves but their duration fiels roughly the same as for receding annuli ie about 4 seconds Waves appear one after another in a cluster with a refractory period between clusters during which no waves appear After a prolonged session ofself-hypnosis the phosphene may not completely dissipate between successive waves in which case the residual phosphene accumulates in a vaguely-circular cloud shape with a small area its center that undergoes continual perturbation the phosphene pulls back leaving a small Mrk circle at the center of the cloud then fills back in then pulls away again ebbing and flowing in like manner until the cloud dissipates At this stage the image resembles an eye with a phosphene iris and a dark inner pupil (C) Twoshytone phosphene During a prolonged session the phosphene at the very center of the amorphous cloud becomes much brighter more fine-grained almost opaque with highly saturated color When a hole (pupil) appears in the center ofthe cloud forming an eyeshyimage the brighter phosphene becomes a thin bright rim lining the Mrk hole from this bright inner rim tiny promontories ofbright phosphene flare out into the Mrk hole twist and coil and collide with other flares forming webs and momentarily filling-in the Mrk hole or receding back into the rim The two-toned phosphene does not only appear in conjunction with the eye-shape clouds it also manifests at the center ofa variety ofelusive ever-changing shapes It is always restricted to the area offoveal vision

(B) PERIODIC UNIDIRECTIONAL AMORPHOUS WAVES These phosphene waves sweep in from one hemifield as shown in Figure 2(B) Often the wave has a vaguely crescent shape at the outset that conforms to the concave curvature of the peripheral VF then the crescent shape gives way as the wave expands rapidly in divergent directions flowing smoothly across the vertical meridian to envelop those regions of the VF that have not yet been illuminated As the leading edge of the wave expands the rear edges are already beginning to dissipate The swirling movement and the contraction of outer boundaries leaves a cloud of phosphene near the center of the VE This cloud may dissipate rapidly or it may persist for several seconds during which a pertur-

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 119

bation takes place at the center of the cloud the phosphene ebbs away from this region leaving a tiny dark hole then the phosphene fills back in then it ebbs and fills again-a fluctuation that continues as long as the phosphene cloud is visible During the perturbations the phosphene vaguely resembles the iris of a human eye with an interior dark space as its pupil This eyeshyimage is seldom symmetrical and its boundaries are always changing

(c) TWO-TONE PHOSPHENE When the phosphenes are induced over a prolonged period of time the phosphene in the central region representing foveal vision presents a more intensely bright more opaque (finely-grained) character than the rest of the cloud as shown in Figure 2(C) When this brilliant opaque phosphene appears as part of an eye-image it forms a thin rim surrounding the pupiL From this rim flares jut out into the dark pupil space coil about merge or recede back into the rim

The periodic unidirectional amorphous waves do not terminate after a stereoshytyped sequence they can be evoked over prolonged rime periods if the autohypshynotic behaviors are maintained The author is unable to retain the vision of these amorphous waves while simultaneously counting the number of seconds elapsed it is his impression however that the duration of amorphous expanding waves feels about the same as for receding annuli that is a duration of about 4 seconds per wave The amorphous waves usually appear in clusters followed by a refractory interval during which no phosphenes appear even if induction behaviors are sustained

PHOSPHENES SUPERIMPOSED ON ExTERNAL OBJECTS

The author can observe amorphous phosphene images with his eyes open if he is in a room dark enough that colors cannot be distinguished or if he is

in a lighted room but one where he can keep his eyes diffusely focused on a relatively undifferentiated surface such as a wall or ceiling with a light and uniform color and no distracting decorative adornments In open-eye viewings phosphenes appear as faint translucent waves of yellow-green mist

superimposed over the surface or in the dark space that fills the darkened room If the author attempts to focus on the features of external objects the phosphenes disappear

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 120

RECEDING ANNuLI EVOKED BY MAGNETIC REsONANCE IMAGING (MRI)

A s a patient undergoing an MRI scan the author observed an unusual sequence of receding annuli He was not relaxed as in a normal induction but rather anxious about his medical condition and about

being confined in the narrow MRI tube To keep calm he concentrated on breathing slowly and stared straight ahead While the sound of MRI machine was audible the author observed a stream of receding annuli that differed from the usual sequence (self-induced and hypnagogic) in three ways (I) the MRI annuli did not terminate at 4 cycles but continued for as long as the author kept his attention focused (2) the MRI annuli were only yellowshygreen in color even though in other inductions the fill-in disk had already changed from green to blue and (3) MRI annuli completed their trajectoshyries in half the normal time disappearing in 2 seconds instead of 4 An interval of 2 seconds between radio pulses is often selected as optimal interval for capture of the signals emitted by hyperexcited atoms in the subjects body

10during the precessional relaxation 9- These observations suggest that energy released in the wake of the radio bombardment during MRI moves through the LGN as a standing wave in the same way that spindle bursts move but that the 2-second duration of the MRI wave is not long enough to activate the neurons that generate a blue sensation

THE ANESTHETIC EFFECT ASSOCIATED WITH SELF-INDUCED

PHOSPHENES

On several occasions the author has preferred to undergo minor surgery without local anesthetic and to rely instead on autohypnotic analgesia-for example during extraction of an infected abscess from the back during laser surgery to

remove keloids and during the filllng of dental caries His experience on a recent occasion when a dentist had to abrade the surface of six teeth with damaged enamel in order to create a strong bonding surface are worth describing here because the experience implies that spindle waves can be induced even during a state of high physiological arousal For this appointshyment the author arrived in the office too late to hypnotize himself in advance

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 121

so he had to begin the normal induction procedures after the dental work was already underway

A s the dentist worked on the first tooth the author experienced apprehension sharp sensations of pain and an involuntary tensing of the large muscles of the body with each application of the drill As

the author kept his eyes converged and his attention focused on the center of the visual field the involuntary tensing in response to pain alternated with a precipitous relaxing of those same muscles immediately after the stimulus With the repeated relaxation came a sense of relief and of letting go that amelioshyrated the pain The pain-driven relaxation was much stronger than the relaxation that normally accompanies the authors self-induction of phosphenes and the alternation of a pain-driven tensing on one hand and the distancing effect of focusing attention on the visual field on the other hand resulted in a rapid dissociation from all external and internal stimuli including a signifishycant amelioration of painful sensations

Most striking is the fact that by the time the dentist reached the third toothshyafter only a few minutes of this pain-driven self-hypnosis-the author saw a normal sequence of 4 receding annuli followed by swirling clouds of amorphous expanding phosphene even though the dentist was still using the drill contemporaneously This experience suggests that thalamic sleep rhythms can be voluntarily induced even when the subjects level of physiological arousal is high

SIMILARITIES WITH ATTENTION-INDUCED PHOSPHENES

REpORTED BY OTHER OBSERVERS

Taxonomies of phosphene images always include examples of simple geometric phosphenes with circular or semi-circular shapes (disks annuli or crescents) as

14well as formless phosphene mists 11 - There are also a number of anecdotal accounts that are relevant for example Friedman an opthamologist who studied entoptic images by introspection describes a similar sequence of annuli induced by sustained inward concentration Circular waves of blue color may be seen in the dark by the dark adapted retina They start at the

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 122

periphery and move inward toward the macula as a concentrically contracting solid circle disappear at the macula and begin again at the peripheryl)

A valuable but often-neglected resource of information about phosphene imagery is presented in the literature of religious mysticism Many mystics reported having seen translucent colored lights while absorbed in prayer or meditation A list of descriptions excerpted from self-reports is presented in Table 1 (These excerpts are representative of phosphene images that appear during states of calm and inward-oriented concentration they do not include images associated with paroxysmal raptures) These phosphene images exhibit a relatively limited set of shapes and colors the shapes are either circular (eg rings disks wheels suns) or formless (eg mists snow smoke) and the colors are usually a variant of either green or blue The phosphene visions of mystics display shapes and colors that are comparable to the images described by the author this and the many similarities in the behaviors used to induce phosphenes suggest that both sets of phosphenes have a common etiology

DISCUSSION

Whether the author uses self-hypnosis to induce phosphenes or experishyences them as hypnagogic images the threshold sequence of receding annuli has the same characteristics In both these

instances the antecedent behaviors involve a state of low physiological arousal combined with mental withdrawal from external stimuli These parallels suggest the hypothesis that phosphene displays are related to sleep-wake transitions

PART I RECEDING ANNULI AND THALAMIC SPINDLES

Mechanisms controlling the transition from waking to NREMS Based on the work of several research teams16-20 a consensus scenario for the generation of NREMS has emerged In this scenario NREMS is the product of three brain rhythms that interact with each other in thalamocorticothalamic circuits During the drowsy transition to sleep which in humans is called stage l NREMS the low voltage activity in the cortical electroencephalograph (EEG) still shows a pattern of intermittent desynchronization The polarization of

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 123

Table I Excerpts from self-reports of light visions by religious mystics

HEBREW MYSTICS the appearance of the wheels was like the gleaming of beryl and the four had the same form

their construction being something like a wheel within a wheel Ezekiel like a dome shining like crystal spread out about their heads And above the dome something

like a rhrone in appearance like sapphire Ezekiel a round Iodder like a full sphere rolling back and forth before him bright blue R Abulafia A glowing light clear brilliance A purple light that absorbs all lights R Moses de Leon

HINDU AND BUDDHIST MYSTICS a perfectly round beautiful deep-blue shape of a size appropriate to the center of a mandala as

if exquisitely painted of extreme c14rity Tsong Khapa a luminous revolving disc studded with lights a lotus flower in full bloom Gopi Krishna both my eyes became cemered When this happened a blue light arose in my eyes like

a candle flame without a wick and stood motionless in the ajna chakra S Muktananda

MUSLIM MYSTICS [like] chandelierssublime lights [like] stars moon or the sun Sharafuddin aI-Maneri its color is deep blue it seems to be an upsurge like water foom a spring Najmoddin Kobra visualize yourself as lying at the bottom of a well [looking up at the light of the opening] and

the well in lively downward movement Najmoddin Kobra the color green is the suprasensory uniting all the suprasensories Alaoddawleh Semnani the light rises in the Sky of the hean taking the form of light-gilling moons Najm Razi

CHRISTIAN MYSTICS his own state at prayer resembles a sapphire it is as clear and bright as the sky Evagrius descending like a bright cloud of mist like a sun round as a circle Simeon Neotheologos saw something in the air near him He did not understand the rype of thing but in some ways

it appeared to have the form of a serpent with many things that shone like eyes although they were not eyes Ignatius of Loyola

the soul puts on a green amilia [cape worn on shoulders beneath armor] John of the Cross [the almilla is like a helmet which] coverS all the senses of the head of the soul It has one

hole rhrough which the eyes may look upwards John of the Cross a round thing about rhe size of a rixdaier all bright and clear with light like a crystal H Hayen I saw a bright light and in this light the figure of a man the color of sapphireblazing with a

gentle glowing fire the three were in one light Hildegard von Bingen saw a b14zing fire incomprehensible inextinguishable with a flame in it the color of the sky

Hildegard von Bingen saw placed beneath her fuet the whole machine of the world as if it were a wheel She saw herself phced

above it her eyes of contemplation magnetized towards the incomprehensible Beatrice of Nazareth I saw the eyes I do not know if I was asleep or awake Angela of Foligno kind of sunlit winged being like a childs head beneath two little wings Abbess Thaisia laquobullbull round patterns small circles would expand and eventually dissipate only to be followed by other small

circles of light Philip St Romain an extraordinary circle of gold light pulsating against a deep violet background There were

always four or fille As soon as one would fode another would appear Philip St Romain

middotItalics added to mark words referring to (l) rings appearing in sets of four (2) amorphous shapes such as clouds or flames (3) circular or eye-like shapes (4) colors from the center of the visible spectrum (gold yellow yellow-green green bluish green) and (5) colors from the lower end of rhe visible spectrum (blue purple violet)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 124

cell membranes (Vm) has already begun to drop (hyperpolarize) in the thalamic reticular nucleus (RTN) a thin sheath of GABAnergic inhibitory neurons that acts as a pacemaker When the Vm of RTN cell membranes drops to approximately V m -60 millivolts (mV) RTN cells stop firing single spikes which are associated with waking states and instead begin firing highshyamplitude 7-14 Hertz (Hz) spike-bursts These bursts wax and wane over 1 to 3 seconds-hence the name spindle -and recur at 3 to 10 seconds Spindle volleys are relayed across the cortical mantle by thalamocortical (TC) sensory relay cells In human studies the primary criterion for onset of the first fullyshyestablished episode of NREMS or stage 2 sleep is the presence of globalized spindles in the cortical EEG

When spindle bursts from the RTN stimulate TC cells to fire in synchrony this synchronous bursting pattern overwhelms the normal capacity of TC cells to relay afferent sensory signals The loss of consciousness at the onset of stage 2 NREMS is thought to be caused by this blocking effect 21

While the RTN is firing spindle bursts through the thalamus another process is activated in the cortex large numbers of cells across the cortical mantle begin to oscillate at a very low frequency laquo 1 Hz)

The cortical slow rhythm referred back to the thalamus via corticothalamic circuits intensifies the hyperpolarizing effect of the RTN spindle bursts on TC cell membranes When V m -75 mV the TC cells begin to generate their own intrinsic calcium currents which further increases hyperpolarization At V m -90 mV the RTN neurons stop firing spindle bursts The TC cells continue to fire low-threshold calcium spikes in patterns which are controlled by the cortical slow rhythm The interaction of these two oscillations generates the delta waves (1 to 4 Hz) which are associated with stage 2 NREMS

In a study of sleep rhythms using the cortical EEG Uchida Atsumi and Kojima found that the mean number of spindles required to induce delta wave activity (that is to induce Vm = -90 mY) is 478 plusmn 162 spindles (from 3 to 7 spindles)22 The mean number of spindles in a volley remains the same for a single individual over multiple trials

Based on the consensus scenario for generation of NREMS we can predict that a phosphene image generated as an epiphenomenon of a thalamic spindle

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 125

Table II Dara show rhe degree of correspondance berween rhe pulse panerns of rhalamic spindles based on intracellular research and rhe sparioremporal panerns of receding annuli phosphenes induced by rhe author using a rechnique of self-hypnosis

Receding annuli phosphenes Thalamic spindle bursrs

Mean number of signals 4 annuli 487 (plusmn 16) bursrs

Sparial exrension vs Thin band 1 - 3 seconds durarion of signal ( 05 -15 cm)

Periodicity of signals 5 seconds 3 - 10 seconds

Simultaneity in LGNs Yes Yes

Point of entry Peripheral VF Ventral amp lareral LGN

Trajecrory Bilareral concentric Unknown

Rare of flow Cons rant rare Unknown

Signal-ro-noise rario High High (shorr bursrs) (sharp brighr discrere)

Termination of sequence Mrer 4 signals Mrer 487 (plusmn 16) signals

will present the following characteristics (1) a high-definition burst-like signal (2) that recurs within 3 to 10 seconds (3) that follows a trajectory compatible with having entered the LGN from the RTN (4) that has a predictable mean for the individual subject and a range that falls somewhere between 2 to 7 annuli and (5) that the spindles will terminate automatically

The temporal patterns of receding annuli and thalamic spindle bursts are similar Table II illustrates the close match between the timing of receding annuli phosphenes and thalamic spindle bursts The most striking similarities are the mean number of signals required to induce termination (4 annuli versus 487 spindles) and the interval between signals (5 seconds for annuli versus 3shyto-lO seconds for spindle bursts) Neither alpha theta nor beta waves present this kind of stereotyped temporal pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 126

T he spatial features of receding annuli are functions of geniculate anatomy A spindle burst moving through the LGN to the cortex will acquire certain distinctive spatiotemporal characteristics because of the

unique curvilinear and laminar anatomy of the LGN A drawing of a macaque LGN based on a clay model constructed by Le Gros Clark23 is shown in Figure 3 The primate LGN is composed of six sheets of cells or laminae that fold over a central hylus In macaques the hylus rises steeply as it extends rostrocausally forming a high arch at the posterior pole in humans the hylus is much more shallow but the functional anatomy is thought to be essentially

23 24the same in both cases - The geometry of the arch forces each lamina to bend so as to constitute in effect one-half of a conical surface and each lamina with its hemi-conical shape contains visual relay cells representing the contralatshyeral half of the visual field (VF) Operating as a pair the complementary hemishycones of the right and left LGN form the functional equivalent of a single conical surface which represents the entire VE This conical geometry of the paired LGNs means a burst of otherwise formless excitation will acquire a distinctive shape as it propagates through the laminae of the LGN Imagine a horizontal section moving along the surface of a cone from base to apex that moving section forms an annulus that shrinks in diameter as it approaches the apex but retains its annular symmetry throughout its trajectory

Figure 3 also includes drawings that show how Connolly and Van Essen24

converted the 3-dimensional structure of lamina 6 the largest and most dorsal layer into a 2-dimensional map Connolly and Van Essen used data obtained by Malpelli and Baker25 to superimpose a grid that specifies the areas in lamina 6 that contain TC cells representing various degrees of isoeccentricity in the VE We will use this map at a later point to show how the movement of a spindle wave through a pair of LGNs correlates with what appears in the VE

The location of the RTN relative to the LGN is also shown in Figure 3 The RTN spindle pacemaker is a thin sheath of GABAnergic inhibitory cells that extends along the surface of the whole posterior ventral thalamus not just the LGN This extension brings the RTN into close proximity with the portion of the LGN (lateral wing) that protrudes out from the main body of the thalamus Some of RTN wraps around and beneath the ventral edges of the LGN26 The RTN comes closest to the LGN in two areas along the ventral edges of the longest laminae (lamina 6 and 1) and along the edge of the lateral

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 127

DORSAL POLE DORSALPOIEA B

L1 L4 L3 L

DORSAL POlE DORSAL POIE (FOVEA)

G LATERAL WING

25

DORSAL POL (FOVEA)

10 _DIAL

20 WING

~

wing These areas contain TC cells that represent the far periphery of the VE If a spindle burst enters the LGN at locations where laminae are in closest proximity to the RTN-along the ventral edges-then the discharge of TC cells will begin in the most ventral portions of the laminae the regions that represent the far periphery of the VE This matches the phosphene sequence observed by the author

Our hypothesis about how this proximity between RTN and LGN affects the trajectory of spindle waves is illustrated in Figure 4 We propose that it is not possible for the author to observe a thin annulus of phosphene sweeping in from all 3600 of the peripheral VF unless spindle bursts exhibit the following

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 128

Figure 3 [facing page Drawings of primate geniculate anatomy and functional anatomy relevant to the generation ofphosphenes (A) Anterior view ofa macaque monkey LGN based on a clay model reconstruction by Le Gros Clark 23 (B) Posterior view ofthe same model showing 6 laminae folded over a central hylus to form lateral and medial wings with the hylus arching steeply upward near the posterior pole to shape the laminae into layers of hollow half-cones nested together Note that the lateral wing of the LGN is slightly larger than the medial wing so that in situ the lateral wing protrudes out from the main body of the thalamus creating a small knob visible during dissection 26 (C) Schematic drawing of an oblique section through median axis (also adapted from Le Gros Clark13 showing how the laminae fuse together at the anterior pole The afferent ganglion cell axons that form the optic tract (OT) penetrate through the anterior surface to reach their target relay cells in the laminae (D) Drawing of the most dorsal lamina-layer 6--separated from the rest of the LGN The geometric shape is a hollow half-cone so that right and left LGNs placed back-to-back form in effect a single cone Note also the position ofthe RTN shown here as a striped bar relative to lamina 6 The position of the striped bar shows that the RTN makes direct contact with lamina 6 at the edge ofthe lateral wing and also along the ventral edges (E - F) Schematic drawings adapted from Connolly and Van Essen24 that show how a 3-dimensional lamina-lamina 6--can be transformed into a 2-dimensional triangular figure lamina 6 is removed and its wings unfolded (E) creating a slightly asymmetric triangular figure (F) which is adjusted to an oblong shape (G) in order to superimshypose a grid matrix with minimal distortion The grid plots locations of TC cells that represent various isoelevations and isoazimuths in the VF locations derived from the experimental observations published by Malpeli and Baker 25 Note the relatively large amounts of laminar surface allocated to central vision (0 0

- 30 0) as compared

to peripheral vision (30 0 - 80 0)

characteristics (1) Spindle bursts must move simultaneously through both geniculate nuclei This pattern of movement is consistent with anatomical studies in primates that found axonal projections linking the right and left RTNs27-28 and with experimental studies in cats that found spindles appearing simultaneously in both right and left thalami 29 (2) Spindle waves must enter the ventral edges of the LGN first and move ventrodorsally in a highly coherent pattern-moving in effect as a standing wave This pattern of movement is consistent with in vitro experiments using sagittal slices from a ferret LGN where spindle waves originated spontaneously at the edge of a slice in an area which contains cells that represent peripheral vision then propagated toward that area of the slice containing cells that represent central vision in the ferret 3o

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 129

VF

PG BIlateral receptive lleJd of PVN YI(j Inward dmKooflality Adapled

0-- from Mortgr at at (1987)

V1

ibull t bull

RTN t t t t t t 1middot3 SECOlO BURSTS OF 7middot14 HZ SPiKES RECURRNG EVERY 3 10 SECONDS

To our knowledge the LGN is the only anatomical structure in the visual system that has the capacity of passively forcing a wave of excitation to flow across a conical surface thereby generating the sensation of a phosphene annulus that retains its symmetry as it shrinks in diameter The retina has a circular anatomy but it is not likely that the mechanical deformation of the retina would produce a wave that began simultaneously in all 3600 of the retinal rim nor that the symmetry of annular wave would be preserved as it flows inward toward the foveal region

The hypothesis presented here-that there is a structure in the visual system that imprints a conical shape on standing waves that move through it-explains

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 130

Figure 4 facing page Schematic drawing of contemporaneous events in selected regions of the visual processing hierarchy (A) The left and right RTNs fire spindle bursts simultaneously (B) The bursts pass through the right and left geniculate laminae as standing waves of depolarization entering from the ventral edges and moving ventrodorsally in parallel In order for the phosphene annulus to appear to be flowing at a constant rate the spindle wave flowing through the LCN must expand in width as it ascends ventrodorsally so that by the time the fill-in disk appears-when the center 30deg of the VF is covered by the phosphene annulus-the spindle wave must have expanded enough to activate relay cells in the most dorsal 50 of lamina 6 (C) Signals representing two complementary hemi-annuli are kept separate in the primary visual cortices (area VI) (D) Signals representing the two hemi-annuli are integrated into signals of a single annulus when they reach area PC in the posterior parietal cortex where the receptive fields of single parietal visual neurons have the capacity to register bilateral signals that exhibit opponent vector movement (that is signals converging from opposite directions along the central axes-as if an object were moving away from the viewer)46 Neurons in area PC also integrate wavelength (color) signals from the extrastriate visual pathway with signals about brightness motion and depth from the parietal visual pathway to compose a representation of an object in space-in this case of an annulus that appears to recede 32

the authors experience during MRI when he observed a continuous succession of receding annuli every 2 seconds in this view the energy of the electroshymagnetic bombardment when released during precessional relaxation flows through the geniculate laminae in the same way that the RTN spindle bursts do that is as a standing wave and thus the visual epiphenomenon is the same in both cases if the subject keeps the eyes focused straight ahead and the attention fixated In a study of phosphenes evoked by electricity in conjunction with hallucinogenic drugs Knoll Kugler Hofer and Lawder found that each subject sees specific kinds of phosphene at different frequencies and that these frequency-specific images are stable enough to be reproduced after six months31

They conclude that the tunability of the electrical stimulation frequenshycies within the EEG range to various definable phosphenes requires the existence of a resonance system One mechanism contributing to that resonance system may be the functional anatomy of the LGN

The colors of receding annuli as functions of geniculate laminar anatomy The colors of receding annuli phosphenes are consistent with the patterns of discharge spindle waves can be expected to stimulate as they move through

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 131

geniculate laminae As shown in Figure 5 the six laminae differ (1) in the types of wavelength signals relayed (2) in physical size and (3) in the area of the VF represented 24-25 Only 4 out of 6 laminae Cparvocellular layers 3shy6) contain TC cells that relay wavelength signals the other 2 laminae (magnocellular layers 1 and 2) do not encode wavelength Among parvocelshylular laminae only lamina 6 the longest and most dorsal layer contains TC cells that can represent the far periphery of the VF (from 800 to 50deg of isoeccenshytdeity) therefore when the spindle wave enters the peripheral VF only those wavelengths relayed by lamina 6 will participate in composing a cortical lightness record (See Zeki)32

I n lamina 6 ganglion cell axons arriving from the retina carry two kinds of wavelength signals (1) center-ON signals from medium-wavelength cones (M-cone center-ON) and long-wavelength cones (L-cone centershy

ON)33-35 Using the cone spectral sensitivity curves (adapted from Marks et al 36) we average the wavelengths that elicit maximal responses for M-cones (535 nanometers) and L-cones (520 nm) which yields a mean wavelength value of 550 nm In humans this wavelength generates a sensation of green or yellowshygreen the sensation observed by the author

As the spindle burst moves ventrodorsally it reaches the dorsal areas in the geniculate laminae which contain TC cells representing the central 0deg to 20deg of isoeccentrieity in the VE All 4 parvocellular laminae have TC cells which are potentially capable of representing this central region of vision but the authors observation that the color of the filling-in disk changed from green to blue implies that in the early years of phosphene induction the spindle wave must have remained close to the surface of the LGN stimulating only laminae 5 and 6 which generates a sensation of yellow-green When the fill-in disk was observed to change color from green to blue the spindle wave must have been rechanneled so that it began to penetrate below laminae 5 and 6 and to activate laminae 3 and 4 the only laminae that relay blue-sensitive signals (Sshycone center-ON signals)3 In light of the authors MRI experience it seems likely that a spindle wave requires a minimum of 2 seconds to reach the blueshysensitive cells of laminae 4 therefore during MRI when the receding annuli disappeared after 2 seconds half the normal duration the fill-disk had a green color even though it had long since change to blue in other induction settings with a 4-second trajectory

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 132

A REPRESENTATION OF THE VISUAL FIELD IN EACH LAMINA

orooqUtftc O-u OCIJ1SALfIOLI (I01flAj

0

10

20

30

40 n50 Of

60

70

20 loO 1Mgr_ II~ o UIpoundAS65 mn1MY-o actlvncL ~~~r

Jll-COMcetlImiddot~

II LAYERSU 3 GatQYancetl~ (1) ucon ceom-oyenF (2)l~cen()FF 3) ~ cenloH

II~ cng1loqctWIIIfNla

iICINe -- (t81Otdb1t1d~OH (2)~

80

B CONE SPECTRAL SENSITIVITY CURVES

S-COHS

WAVIlLllNG1llS OF UGHT IH NANOMllTERS (NM)

Figure 5 Phosphene color as a function of ganglion cell distribution in parvocellular laminae (Aj Schematic drawing ofthe proportion ofthe VF represented in each laminae The proportions shown here are based on the work of Connolly and Van Essen24 The

far periphery of vision (50 0 to 80 0 of isoeccentricity) is represented in only two laminae-laminae 1 and 6-and of these two only lamina 6 is a parvocelLular lamina capable ofencoding wavelength signals Therefore only those wavelengths relayed by lamina 6 will participate in forming a cortical lighmess record for the far periphery of the VP (B) Cone spectral sensitivity curves (adapted from Marks et al)36 Using these cone sensitivity curves we can estimate the sensation stimulated by a spindle wave moving through lamina 6 by averaging the wavelengths that elicit maximal responses for M-cones (535 nanomeshyters) and L-cones (520 nm) which yields a mean wavelength value of550 nm In humans this generates a sensation of green or yellow-green the sensation observed by the author when the receding annulus enters at the far periphery of the VP For a calculation of the cortical lightness record when a spindle wave moves through 20deg to 0deg ofthe VF stimulating all 4 parvocelfular laminae see the text and Figure 6

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 133

Once the spindle wave penetrates to laminae 3 and 4 it may activate all 4 parvocellular laminae stimulating TC cells to send contradictory wavelength signals for the same retinotopic location the signals sent from laminae 4 and 3 will encode blue light (S-cone center-ON plus M-cone center-OFF and Lshycone center-OFF) while the signals sent from laminae 5 and 6 encode yellowshygreen light (M-cone center-ON plus L-cone center-ON) This kind of contrashydiction does not occur in normal retina-based perception where light energy striking the retina is structured by the retinas center-surround and colorshyopponent organization to encode only one set of wavelength signals for each spatial locus 32 In Figure 6 we estimate the cortical lightness record that results when contradictory wavelength signals compete to be represented in consciousshyness Our calculations suggest that the outcome will be a mean wavelength which in humans elicits a dark blue or violet sensation

PART II AMORPHOUS PHOSPHENES amp THALAMIC DELTA ACTMTY

M echanisms controlling the transition from spindle bursts to delta activity In the consensus scenario for the generation of NREMS16-20 we noted that the RTN shifts to firing spindle bursts

when polarization of thalamic cell membranes drops to V m = - 60 mV At the same time cortical cells begin oscillating with a synchronous slow rhythm laquo 1 Hz) Both processes further decrease the Vm of TC cell membranes When Vm = - 75 mY TC cells begin to generate their own intrinsic calcium currents which also decreases V m At V m = - 90 mV RTN neurons stop firing spindle bursts At the same time the TC cells begin firing low-threshold calcium spikes in alternation with after-hyperpolarizations (LTS-AHP) Because sensory relay neurons in the LGN are not linked to one another by locally projecting axons the firing of one TC cell does not excite its neighbor However a lack of local connectivity does not mean that TC cells occupying the same laminae release their AHP-LTS calcium spikes in a random distribshyution rather spikes are released simultaneously by groups of cells in synchrony with the advent of the cortical slow wave In effect the distribution of LTSshyAHP spikes firing in the LGN is determined by the spatial propagation of the cortical slow wave Thus the delta wave (1 to 4 Hz) activity detected by cortical EEG during NREMS is a product of the interaction between the AHP-LTS calcium spikes released by TC cells and the cortical slow rhythm

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 134

CORTICAL PROCESSING OF CONTRADICTORY

WAVELENGTH SIGNALS

KEY _ Cells firing

cJ Cononol firing

Assume that as a spind6e wave moves through the LGNlt fires simultaneously aU the TC cells that represent a particular reUnoshytopic locus (x y) in each of the six laminae As a result cortical cells engaged In the higher level processing of visual signals will receive more wavelength signals representing retina locus (x y) than are generated by normal perception laquo and some of these afferent wavelength signals may contradict other signals arriving simultaneously

CORTICAL LIGHTNESS RECORD SlgnalSell

Intemal contradictions not congruent wilt pre

SmiddotON eristing neuron neta

s bullbull M-ON LmiddotON

3 bullbull M-OFF + L-OFF

a-ON 12

ROD-ON

No Internal eonlradlemiddot

--------1I =~8b~~~~~~~t signals

3+4

~ --OFF Excludes 6 Of 7 $J9n18

1+2 B-ON I

IWmiddotHmiddotI Signal Sell

1111111 No Intern1 conlrfldlcshy lion

Exelvdta 4 out of 7 efshy

bullbullbull bullbullbull ferant signals

No Intern1 contradic_ tionnee S-ON BshyOH and ROO-ON can all be coacllve at low lImlnance levels nef Ihe rod-eone break

ExchJde$ only 2 Ollt of 7 afferent signals

Figure 6 Selection of competing wavelength signals based on neuronal group selection This thought experiment is based on Edelman sconcept ofneuronal group selection 73 We assume that all possible combinations ofsignals will form sets and that all signal-sets will compete to make the most efficient match with pre-existing neuromd networks that have been forged over years ofnorma reti1U1-based perception We also assume that pre-existing neural networks are most likely to expedite those sets that satisfY 2 criteriI (J) the signals in a set do not contradict each other and (2) fower signals are excluded than in the other sets that satisfY the first criterion In our analysis Set 4 wins the competition because it does not contain internal contradictions and excludes fower signals (2 out of 7) than Set 3 excludes (4 out of7) It is not an internal contradiction that Set 4 contains both rods and cone Signtlls in normal retina-based perception when luminance levels approach the rod-cone break S-cone center-ON receptors send signas as do rod receptors and there is even evidence that rod activity may actually drive S-cone activity even after luminance levels foIl below the rod-cone break74 To calculate the cortical lightness record for Set 4 we average the wavelength that elicits maximal responses foom rods (511 nm) and for Sshycones (430 nm) which yields a mean wavelength of 470 nm which in humans results in a dark-blue or violet sensation

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 135

The cortical slow rhythm is an example of a generic pattern of neuronal excitashytion that occurs in large networks of neurons linked by local projections A recent experiment by Maeda Robinson and Kwana38 shows that networks of locally-connected neurons spontaneously generate periodic synchronized bursts of calcium transients that propagate across the network in an expanding spatial wave a pattern that represents a stable mode of firing towards which these neuronal networks relax following perturbations for example by electronic stimulation or by drugs Understanding the characteristics of these waves is an important prerequisite to understanding the mechanisms that produce the amorphous phosphene images as a visual epiphenomenon

To study the spontaneous periodic synchronized bursts the researchers prepared cultures of dissociated cortical neurons and allowed them to mature for several days in vitro (DIV) After 3 to 4 DIV when concenshy

trations of extracellular magnesium were low electrodes began to detect spontaneous synchronized bursts of low frequency calcium transients (between 01 and 1 Hz) that originated in different locations on the sheet every 10 to 20 seconds and spread across the sheet of cells at a relatively slow speed averaging 50 mmsecond The researchers could not predict where a wave would originate or where it would expand rather the initiation and expansion of waves was generated by spatial and temporal summation of a continuous random background of synaptic inputs including miniature spontaneous synaptic events but the pattern was not random since waves propagated sequentially from electrode to electrode as each local group of neurons charges up its neighboring nontefractory areas rather than in a random sequence of regions38

The excitability of the cells in the sheet determines the probability first that there will be a synchronous burst and second that it will spread in a particshyular direction Cells become more excitable as the cultures mature which means the refractory intervals between successive bursts were much shorter in mature cultures (gt 30 DIV) than in early cultures laquo 7 DIV) Some cells became so insensitive to inhibition that they continued to fire bursts even when extracellular concentrations of magnesium were relatively high Finally there were refractory periods of 5 to 10 seconds during which no bursts occurred even when an electrical stimulus was applied This refractory interval for cultured networks is slightly longer than the refractory interval observed of the cortical slow wave in vivo which 25 to 4 seconds 18- 19

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 136

Based on the observations about cortical slow waves we can predict that phosphenes generated as epiphenomena of delta wave activity will present the following signal characteristics (1) signals that appear at unpredictable locations in the VF (2) signals that expand and diverge asymmetrically following unpredictable trajectories which may encompass large areas of the VF (3) signals that move relatively slowly (50 mmsec) (4) signals that recur with a period of 2 to 4 seconds reflecting entrainment by the cortical slow wave (5) signals that do not terminate automatically after a predictable number of cycles

The spatial patterns of phosphene mists and thalamic delta waves are similar The spatiotemporal characteristics of amorphous phosphenes match the pattern of wave propagation associated with periodic spontashy

neous synchronized bursts in large neuron networks the amorphous phosphenes enter the visual field at unpredictable locations expand and diverge asymmetrically with a slow steady rate of flow follow trajectories that are unpredictable and exhibit a refractory interval The amorphous mists do appear to have a periodicity although the author is unable to sustain the vision while also counting the seconds therefore he is unable to determine if it compares to the period of the cortical slow wave (25 to 4 seconds) but his impression is that it feels roughly the same as as with receding annuli which recur at 5 seconds Also the refractory interval feels as if it decreases as the induction session is extended These similarities suggest that the amorphous phosphenes are generated by stage 2 NREMS delta wave activity which is an activity governed by the reverberation of the cortical slow wave in thalamoshycorticothalamic circuits The cortical slow wave is referred to the LGN where it modulates the firing of visual relay cells in the laminae and since relay cells do not have local dendritic connections the expansion of a wave of depolarshyizations moving from one relay cell to the next across in the laminar surface will mirror at least in part the expansion of the cortical wave that is spreading contemporaneously through locally-connected cortical cells

PART III RETENTION OF CONSCIOUSNESS

In a normal transition to NREMS the volley of synchronous spindle bursts that marks the onset of stage 2 NREMS overwhelms the normal firing pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 137

of thalamocortical cells preventing their relay of afferent sensory signals and inducing a loss of consciousness21 But the loss of consciousness cannot be timed precisely using cortical EEG the thalamus is too remote for the onset of spindling to be reliably detected by scalp electrodes39 In experiments with cats where electrodes could be implanted in the thalamus researchers found that spindling often reached peak levels of activity in the thalamus-a level of activity consonant with stage 2 NREMS-at a time when the cortical EEG was still showing intermittent desynchronizations a pattern characteristic of the drowsy stage 1 transition not a fully-established stage 2 NREMS episode4o

In other words there is a short period of time in which the synchronous rhythms of stage 2 NREMS are installed in the thalamus but not in the cortex where cortical neurons continue to depolarize in response to afferent sensory signals

T his finding suggests a possible explanation for the authors ability to retain consciousness while spindle bursts are sweeping through the LGN if he is able to extend the duration of this time lag between

the onset of spindling in the thalamus and spindling in the cortex if he is able to stimulate the visual cortices in such a way that they continue to depolarize then he may be able to keep on processing visual signals-to remain visually aware-even after the non-visual thalamus and non-visual cortex become entrained by synchronous sleep rhythms The authors induction technique includes several behaviors which are known to enhance the responsiveness of visual neurons-eye movements attentive fixation and an attitude of expectancy

Effects of eye movements and attention on the LGN Sustained convergence causes periorbital proprioceptors to send excitatory feedback directly to the LGN41 Also convergence further enhances the excitability of geniculate cells by stimulating the superior collicus (SC) which sends its own excitatory signals to the LGN42-43 These signals from the SC are known to selectively enhance the excitability of visual relay cells that represent the periphery of vision44 We know in the authors case that the SC is being stimulated because he is able to keep on fixating an ability which would normally be lost during the transishytion to NREMS45 The ability to fixate can be retained however if the SC is stimulated (even if stimulated during NREMS)46

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 138

Effects of eye movement attention and expectancy on the primary visual cortex The PET study of mental imagery by Kosslyn et al 3 showed that even a baseline resting state of relaxed immobile expectancy can generate signifishycant increases in neuronal activity in the primary visual cortices Further increases can be induced by sustained eye movements

A sustained convergence will release a stream of ponto-geniculo-occipital (PGO) waves These PGO waves called eye movement potentials or EMPs last only as long as the eye movement1747 whereas the PGO waves associated with rapid-eye-movement sleep (REMS) fire continually for the duration of the REMS episode Both REMS-related PGO waves and EMPs have the same desynchronizing effect on the visual pathways they move through the LGN depolarizing the thalamocortical cells which relay the signals to cortical neurons The responsivity of neurons in the primary visual cortices is enhanced by the stimulation of PGO waves 1747-49 If the passage of EMPs causes the genicushylate relay cells and their cortical targets to depolarize regularly then a volley of 4 spindle bursts moving through the same pathways will register as just another series of depolarizations in effect the spindle bursts are processed by the visual system as if they were sensory signals sent from the retina rather than an event stimulated by endogenous mechanisms

T he impact of eye movements and ftxation on the parietal visual cortex Convergence and attentive fixation will also enhance the responsiveness of light-sensitive parietal visual neurons (PVNs) in area PG of the

posterior parietal cortex 50 In experiments where monkeys are trained to fix their attention on a screen-and to keep on fixating even if no targets appearshythe excitability of these light-sensitive PVNs increases by as much as 350 51

52-53Responsiveness is also facilitated by the angle of gaze Also area PG is the first region in the visual pathways containing individual neurons with the capacity to respond to large bilateral stimuli moving in opposite directions along the central meridians of vision (opponent vector motion) 853-55 Facilitation of PVNs in area PG has the effect of sensitizing the subject to bilateral opponent vector motion and this is especially true if the movement appears in the periphery of the VE 8

Intracortical ampliftcation and feedback to the LGN When PGO waves and signals from the SC arrive in the primary visual cortex they may be relatively weak however weak signals can be amplified by reverberating in large networks

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 139

of cortical cells linked by local projection 56 There are nine times as many excitatory links among cortical cells as there are projections from the visual cortex to the LGN an imbalance which suggests leads Suarez Koch and Douglas to propose that geniculate input provides only a minor fraction of the excitatory input the majority originating in neighboring and recurrently connected cortical cells57 If the excitabiliry of cortical neurons is slightly higher than normal then this process of amplification may continue even after the LGN signals that initiated the reverberation are no longer being transmitted by the LGN ( a hysteretic mode of operation) 57

Feedback from hyperexcited cortical neurons will stream back to the LGN via corticogeniculate projections which outnumber geniculocortical projections ten-to-one One effect of this feedback is that the LGN is

able to absorb large amounts of information flowing back from the cortex 58

As signals reverberate back and forth in thalamocorticothalamic circuits a matching process takes place those geniculate relay cells that fire in patterns consistent with the firing patterns of active cortical cells will have their responshysivity enhanced while those geniculate cells that fire in patterns not consistent with cortical cells will be suppressed 59

Preservation of consciousness by selective facilitation of the visual pathways By combining all of the facilitatory effects produced by the authors eye movements and attentive fixation-(l) stimulation of the LGN by feedback from periorbital proprioception both directly and indirectly via the SC (2) the release of PGO waves (EMPs) that facilitate neurons in the LGN and primary visual cortex as they pass (3) the facilitation of the primary visual cortex by a state of relaxed immobile expectancy (4) attentive fixation and angle of gaze that facilitate PVNs in area PG (5) intracortical amplification of signals received from the LGN and (6) corticogeniculate feedback that stimulates the LGN-we delineate a circuit of enhanced excitability that extends from the LGN through the post-geniculate visual heirarchy to area PG where signals are integrated into representations of objects

The hyperexcitability of neurons all along the post-geniculate visual pathways creates conditions in the visual cortices which are similar to those present during EEG-desynchronized states of waking and REMS Therefore neurons in the visual pathways are too excitable to be entrained by synchronous bursting

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 140

patterns when spindle waves move through them instead the spindle bursts stimulate visual neurons to depolarize and then recover as happens in response to afferent sensory signals during waking states It is important to note that for this to occur none of the constituent neuron assemblies is required to perform an abnormal operation the abnormality is a function of the authors intent to activate contemporaneously neuron assemblies that would not normally be co-activated

PART IV HYPNOTIC ANALGESIA

Manipulation of spatial attention as a method for alleviating pain sensations In a theoretical article on the neurophysiology of hypnosis Crawford and Gruzelier60 propose that variations in hypnotizability are function of variability in the efficiency of the frontolimbic (anterior) attentional system in humans high-hypnotizables are better able to sustain focused attention on a task and to ignore extraneous stimuli than are low-hypnotizables

I na related empirical study that compares the use of attention by subjects with high versus low hypnotizability Crawford Brown and Moon61 report that highly hypnotizable persons continue to show physiological reactivity

while cognitively not perceiving the painful stimuli Through disattentional processes they can dissociate themselves from the awareness of pain The authors phosphene induction behaviors-and the cutaneous analgesia he experishyences-appear to involve the same kind of behaviors that is a mobilization of frontolimbic attention used to withdraw attention from external stimuli and to concentrate it on internally-generated phosphene images This suggests the hypothesis that the mechanisms that generate phosphenes might also produce hypnotic analgesia There are several ways that visual signals and pain signals might interact to produce this analgesia

Competition between pain and vision signals for limbic registration The fully-developed sensation of pain requires integration of rwo kinds of informashytion Signals that encode the location and intensity of a noxious stimulus (nociceptive signals) are relayed via the thalamus to the somatosensory cortices which registers only the sensory-discriminative aspects of pain perception62 before reaching consciousness the nociceptive signals must be sent to the limbic

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 141

system where they are linked with signals from long-term memory that encode the affective significance the stimulus has acquired for that individual Studies of brain metabolism show this linking of somatosensory information with limbic associations takes place in the anterior cingulate (CG) and anterior insula62-64

PET studies also show that the anterior CG is activated when subjects shift their spatial attention in response to expectations as to where

66stimuli will next appear65- This is precisely what takes place during the state of immobile expectancy that induces phosphenes Since visual signals and nociceptive signals both require limbic enhancement which is only possible if they get access to the anterior CG there might be conditions in which the two types of afferent sensory signals have to compete for that access In a theoretical article on the mechanisms of attention Posner and Rothbart67

propose that visual signals can interfere with nociceptive signals by blocking access to the anterior CG As behavioral evidence they cite studies showing that when young infants make distress calls they can be distracted by the presentation of a new visual stimulus We have shown the evidence of such control at about three months Orienting to visual events can be employed to quiet or calm negative vocalizations However the distress appears to be maintained and reappears when the infants attention to the stimulus is reduced Caregivers also report the use or visual orienting to block overt manifestations of distress at about this age 67

The effects of disattention on the somatosensory cortices If there is a competition between visual signals and nociceptive signals for access to the anterior CG it is likely that the competition will be affected by the relative volume of signals received A recent study suggests that focusing attention on internally-generated visual stimuli may reduce the number of nociceptive signals relayed by the somatosensory cortices Drevets Burton Videen Snyder Simpson and Raichle68 have shown that the mere anticipation of a touch at a specific cutaneous site increases the flow of blood to those cortical somatosenshysory neurons that are linked with that site where touch is expected and decreases the flow of blood to neurons linked with sites where touch is not expected In this experiment the researchers designated touch as the behaviorally significant sensory stimulus but their findings suggest that the outcome could be reversed if the instructions were reversed if subjects were

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page J42

instructed to direct attention away from a cutaneous site where a noxious stimulus was being applied if they were instructed to relax close their eyes and concentrate on the play of phosphenes in the visual field as the behaviorally significant sensory stimulus then it would be reasonable to expect that the flow of blood would decrease to the somatosensory neurons linked with the cutaneous stimulus and that the flow of blood would increase to the visual cortices The decrease in blood flow to somatosensory neurons implies less neuronal activity which implies that fewer signals are being sent forward to the anterior CG than would have been sent if instead the subject were treating the touch as the behaviorally significant sensory stimulus If fewer pain signals arrive at the anterior it is reasonable to infer that the conscious experience of pain will be muted by the diversion of attention to internal visual stimuli

Differential impact of sleep rhythms in the visual and nonvisual thalamus There is another mechanism that might also contribute to the analgesic effect of inducing sleep rhythms PET studies show that

the thalamus is involved in the relay of nociceptive signals to the cortex63 although some confusion remains about which kinds of signals are relayed by which subregions in the thalamus62 One thalamic site clearly identified by anatomical studies as a relay for nociceptive signals is the ventroposterior lateral nucleus (VPL)69 If synchronous sleep rhythms are active in the thalamus we can reasonably expect that the VPL will itself be entrained by synchronous oscillations and that it will relay the sleep rhythms to somatosensory cortices Relay neurons in the VPL are not stimulated by feedback from eye movements and fixation as are relay neurons in the LGN which suggests that sleep rhythms may impede the relay of nociceptive signals via the VPL but not the relay of visual signals via the LGN

Brain waves associated with anesthesia and NREMS The hypothesis presented here-that consciousness can be preserved despite the presence of NREMS activity-is consistent with a recent report that the kinds of fast brain waves which are normally associated with conscious states are also present during NREMS and anesthesia two states which were thought to involve minimal brain activityJo Another recent study found that there is a close resemblance between the slow brain waves that appear during NREMS and those that appear during certain types of anesthesia71

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 143

bull bull bull

CONCLUSION

In this paper we have presented evidence supporting the hypothesis that phosphene images can be generated as an epiphenomena of thalamic spindle bursts and delta wave activity normally associated with NREMS The prereqshyuisites for inducing these sleep rhythm phosphenes are relaxed immobile expectancy sustained convergence and attentive fixation of an undifferentiated visual field Our hypothesis provides a necessary and sufficient explanation for the authors induction of phosphenes and perhaps also for the generation of phosphenes reported to appear spontaneously during the drowsy transition to sleep (hypnagogic states) during sensory deprivation or during certain kinds of prayer or meditation all of which involve a similar state of relaxed immobile expectancyJ2

CORRESPONDENCE Philip T Nicholson bull 52 Norfolk Road bull Chestnut Hill MA 02167

REFERENCES amp NOTES

1 M 1 Posner Modulation by Instruction Nature 373 (1995) pp 198-199 2 J Reissenweber E David amp M pfotenhauer Investigations of Psychological Aspects of

the Perception of Magnetophosphenes and Electrophosphenes Biomedizinische Tecknik 373 (1992) pp 42-45

3 S M Kosslyn W L Thompson 1 J Kim amp N M Alpert Topographical Representations of Mental Images in Primary Visual Cortex Nature 378 (I995) pp 496-498

4 P E Roland amp B Gulyas Visual Memory Visual Imagery and Visual Recognition of Large Field Patterns by the Human Brain Functional Anatomy by Positron Emission Tomography Cerebral Cortex 51 (1995) pp 79-93

5 H Benson The Relaxation Response (Morrow New York NY 1975) 6 ] H Schultz amp W Luthe Autogenic Training a Physiological Approach to Psychotherapy

(Grune amp Stratton New York NY 1969) 7 E Jacobson Progressive Relaxation (University of Chicago Press Chicago IL 1938) 8 M A Steinmetz BC Motter C] DuffY amp V B Mountcastle Functional Properties

of Parietal Visual Neurons Radial Organization of Directionalities Within the Visual Field Journal ofNeuroscience 71 (1987) pp 177-191

9 R R Edelman Magnetic Resonance Imaging of the Nervous System Discussions in Neuroscience 71 Elsevier Science Amsterdam (I990) also J H Newhouse amp ] I Wiener Understanding MRI 1st Ed (Little Brown Boston MA 1991)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 144

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

10 seconds 15 sec 20 sec

25 Bee 30 sec 35 sec

expand and curl aimlessly then dissipate Because these waves are so unpredictable and formless the author is unable to predict the mean number of signals per episode the period between signals the site of entry or exit or to define a typical trajectory other than in the abstract generic manner used above The signal-to-noise ratio in these phosphenes is very low since phosphene stands out against the background there clearly is a signal but this signal presents so little pattern that it is essentially a form of phosphene noise These localized pulsations may continue for several minutes but usually within a minute or two they are superceded by the type of amorphous wave described next

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 118

Figure 2 [focing page Schematic drawings of of amorphous expanding phosphenes (A) Brief randomly-dispersed localized pulses These phosphenes are the first to appear after the receding annuli They coalesce at unpredictable locations in the IF expand asymmetrically for a second or two then dissipate into eigengrau before there is time to extend very for beyond their locus of origin (B) Periodic unidirectional amorphous expanding waves These phosphene waves enter the periphery ofvision from one hemifield presenting as a loosely-defined crescent (hemi-annular) cloud that mirrors the curvature of the peripheral rim The leading edge of the wave expands and flows across the vertical meridian into the opposite hemified swirling around the periphery curling inward and merging while at the same time the trailing edge ofphosphene dissipates rapidly in those regions over which the wave has already passed like mist or smoke evaporating in air The author is unable to time these waves but their duration fiels roughly the same as for receding annuli ie about 4 seconds Waves appear one after another in a cluster with a refractory period between clusters during which no waves appear After a prolonged session ofself-hypnosis the phosphene may not completely dissipate between successive waves in which case the residual phosphene accumulates in a vaguely-circular cloud shape with a small area its center that undergoes continual perturbation the phosphene pulls back leaving a small Mrk circle at the center of the cloud then fills back in then pulls away again ebbing and flowing in like manner until the cloud dissipates At this stage the image resembles an eye with a phosphene iris and a dark inner pupil (C) Twoshytone phosphene During a prolonged session the phosphene at the very center of the amorphous cloud becomes much brighter more fine-grained almost opaque with highly saturated color When a hole (pupil) appears in the center ofthe cloud forming an eyeshyimage the brighter phosphene becomes a thin bright rim lining the Mrk hole from this bright inner rim tiny promontories ofbright phosphene flare out into the Mrk hole twist and coil and collide with other flares forming webs and momentarily filling-in the Mrk hole or receding back into the rim The two-toned phosphene does not only appear in conjunction with the eye-shape clouds it also manifests at the center ofa variety ofelusive ever-changing shapes It is always restricted to the area offoveal vision

(B) PERIODIC UNIDIRECTIONAL AMORPHOUS WAVES These phosphene waves sweep in from one hemifield as shown in Figure 2(B) Often the wave has a vaguely crescent shape at the outset that conforms to the concave curvature of the peripheral VF then the crescent shape gives way as the wave expands rapidly in divergent directions flowing smoothly across the vertical meridian to envelop those regions of the VF that have not yet been illuminated As the leading edge of the wave expands the rear edges are already beginning to dissipate The swirling movement and the contraction of outer boundaries leaves a cloud of phosphene near the center of the VE This cloud may dissipate rapidly or it may persist for several seconds during which a pertur-

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 119

bation takes place at the center of the cloud the phosphene ebbs away from this region leaving a tiny dark hole then the phosphene fills back in then it ebbs and fills again-a fluctuation that continues as long as the phosphene cloud is visible During the perturbations the phosphene vaguely resembles the iris of a human eye with an interior dark space as its pupil This eyeshyimage is seldom symmetrical and its boundaries are always changing

(c) TWO-TONE PHOSPHENE When the phosphenes are induced over a prolonged period of time the phosphene in the central region representing foveal vision presents a more intensely bright more opaque (finely-grained) character than the rest of the cloud as shown in Figure 2(C) When this brilliant opaque phosphene appears as part of an eye-image it forms a thin rim surrounding the pupiL From this rim flares jut out into the dark pupil space coil about merge or recede back into the rim

The periodic unidirectional amorphous waves do not terminate after a stereoshytyped sequence they can be evoked over prolonged rime periods if the autohypshynotic behaviors are maintained The author is unable to retain the vision of these amorphous waves while simultaneously counting the number of seconds elapsed it is his impression however that the duration of amorphous expanding waves feels about the same as for receding annuli that is a duration of about 4 seconds per wave The amorphous waves usually appear in clusters followed by a refractory interval during which no phosphenes appear even if induction behaviors are sustained

PHOSPHENES SUPERIMPOSED ON ExTERNAL OBJECTS

The author can observe amorphous phosphene images with his eyes open if he is in a room dark enough that colors cannot be distinguished or if he is

in a lighted room but one where he can keep his eyes diffusely focused on a relatively undifferentiated surface such as a wall or ceiling with a light and uniform color and no distracting decorative adornments In open-eye viewings phosphenes appear as faint translucent waves of yellow-green mist

superimposed over the surface or in the dark space that fills the darkened room If the author attempts to focus on the features of external objects the phosphenes disappear

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 120

RECEDING ANNuLI EVOKED BY MAGNETIC REsONANCE IMAGING (MRI)

A s a patient undergoing an MRI scan the author observed an unusual sequence of receding annuli He was not relaxed as in a normal induction but rather anxious about his medical condition and about

being confined in the narrow MRI tube To keep calm he concentrated on breathing slowly and stared straight ahead While the sound of MRI machine was audible the author observed a stream of receding annuli that differed from the usual sequence (self-induced and hypnagogic) in three ways (I) the MRI annuli did not terminate at 4 cycles but continued for as long as the author kept his attention focused (2) the MRI annuli were only yellowshygreen in color even though in other inductions the fill-in disk had already changed from green to blue and (3) MRI annuli completed their trajectoshyries in half the normal time disappearing in 2 seconds instead of 4 An interval of 2 seconds between radio pulses is often selected as optimal interval for capture of the signals emitted by hyperexcited atoms in the subjects body

10during the precessional relaxation 9- These observations suggest that energy released in the wake of the radio bombardment during MRI moves through the LGN as a standing wave in the same way that spindle bursts move but that the 2-second duration of the MRI wave is not long enough to activate the neurons that generate a blue sensation

THE ANESTHETIC EFFECT ASSOCIATED WITH SELF-INDUCED

PHOSPHENES

On several occasions the author has preferred to undergo minor surgery without local anesthetic and to rely instead on autohypnotic analgesia-for example during extraction of an infected abscess from the back during laser surgery to

remove keloids and during the filllng of dental caries His experience on a recent occasion when a dentist had to abrade the surface of six teeth with damaged enamel in order to create a strong bonding surface are worth describing here because the experience implies that spindle waves can be induced even during a state of high physiological arousal For this appointshyment the author arrived in the office too late to hypnotize himself in advance

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 121

so he had to begin the normal induction procedures after the dental work was already underway

A s the dentist worked on the first tooth the author experienced apprehension sharp sensations of pain and an involuntary tensing of the large muscles of the body with each application of the drill As

the author kept his eyes converged and his attention focused on the center of the visual field the involuntary tensing in response to pain alternated with a precipitous relaxing of those same muscles immediately after the stimulus With the repeated relaxation came a sense of relief and of letting go that amelioshyrated the pain The pain-driven relaxation was much stronger than the relaxation that normally accompanies the authors self-induction of phosphenes and the alternation of a pain-driven tensing on one hand and the distancing effect of focusing attention on the visual field on the other hand resulted in a rapid dissociation from all external and internal stimuli including a signifishycant amelioration of painful sensations

Most striking is the fact that by the time the dentist reached the third toothshyafter only a few minutes of this pain-driven self-hypnosis-the author saw a normal sequence of 4 receding annuli followed by swirling clouds of amorphous expanding phosphene even though the dentist was still using the drill contemporaneously This experience suggests that thalamic sleep rhythms can be voluntarily induced even when the subjects level of physiological arousal is high

SIMILARITIES WITH ATTENTION-INDUCED PHOSPHENES

REpORTED BY OTHER OBSERVERS

Taxonomies of phosphene images always include examples of simple geometric phosphenes with circular or semi-circular shapes (disks annuli or crescents) as

14well as formless phosphene mists 11 - There are also a number of anecdotal accounts that are relevant for example Friedman an opthamologist who studied entoptic images by introspection describes a similar sequence of annuli induced by sustained inward concentration Circular waves of blue color may be seen in the dark by the dark adapted retina They start at the

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 122

periphery and move inward toward the macula as a concentrically contracting solid circle disappear at the macula and begin again at the peripheryl)

A valuable but often-neglected resource of information about phosphene imagery is presented in the literature of religious mysticism Many mystics reported having seen translucent colored lights while absorbed in prayer or meditation A list of descriptions excerpted from self-reports is presented in Table 1 (These excerpts are representative of phosphene images that appear during states of calm and inward-oriented concentration they do not include images associated with paroxysmal raptures) These phosphene images exhibit a relatively limited set of shapes and colors the shapes are either circular (eg rings disks wheels suns) or formless (eg mists snow smoke) and the colors are usually a variant of either green or blue The phosphene visions of mystics display shapes and colors that are comparable to the images described by the author this and the many similarities in the behaviors used to induce phosphenes suggest that both sets of phosphenes have a common etiology

DISCUSSION

Whether the author uses self-hypnosis to induce phosphenes or experishyences them as hypnagogic images the threshold sequence of receding annuli has the same characteristics In both these

instances the antecedent behaviors involve a state of low physiological arousal combined with mental withdrawal from external stimuli These parallels suggest the hypothesis that phosphene displays are related to sleep-wake transitions

PART I RECEDING ANNULI AND THALAMIC SPINDLES

Mechanisms controlling the transition from waking to NREMS Based on the work of several research teams16-20 a consensus scenario for the generation of NREMS has emerged In this scenario NREMS is the product of three brain rhythms that interact with each other in thalamocorticothalamic circuits During the drowsy transition to sleep which in humans is called stage l NREMS the low voltage activity in the cortical electroencephalograph (EEG) still shows a pattern of intermittent desynchronization The polarization of

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 123

Table I Excerpts from self-reports of light visions by religious mystics

HEBREW MYSTICS the appearance of the wheels was like the gleaming of beryl and the four had the same form

their construction being something like a wheel within a wheel Ezekiel like a dome shining like crystal spread out about their heads And above the dome something

like a rhrone in appearance like sapphire Ezekiel a round Iodder like a full sphere rolling back and forth before him bright blue R Abulafia A glowing light clear brilliance A purple light that absorbs all lights R Moses de Leon

HINDU AND BUDDHIST MYSTICS a perfectly round beautiful deep-blue shape of a size appropriate to the center of a mandala as

if exquisitely painted of extreme c14rity Tsong Khapa a luminous revolving disc studded with lights a lotus flower in full bloom Gopi Krishna both my eyes became cemered When this happened a blue light arose in my eyes like

a candle flame without a wick and stood motionless in the ajna chakra S Muktananda

MUSLIM MYSTICS [like] chandelierssublime lights [like] stars moon or the sun Sharafuddin aI-Maneri its color is deep blue it seems to be an upsurge like water foom a spring Najmoddin Kobra visualize yourself as lying at the bottom of a well [looking up at the light of the opening] and

the well in lively downward movement Najmoddin Kobra the color green is the suprasensory uniting all the suprasensories Alaoddawleh Semnani the light rises in the Sky of the hean taking the form of light-gilling moons Najm Razi

CHRISTIAN MYSTICS his own state at prayer resembles a sapphire it is as clear and bright as the sky Evagrius descending like a bright cloud of mist like a sun round as a circle Simeon Neotheologos saw something in the air near him He did not understand the rype of thing but in some ways

it appeared to have the form of a serpent with many things that shone like eyes although they were not eyes Ignatius of Loyola

the soul puts on a green amilia [cape worn on shoulders beneath armor] John of the Cross [the almilla is like a helmet which] coverS all the senses of the head of the soul It has one

hole rhrough which the eyes may look upwards John of the Cross a round thing about rhe size of a rixdaier all bright and clear with light like a crystal H Hayen I saw a bright light and in this light the figure of a man the color of sapphireblazing with a

gentle glowing fire the three were in one light Hildegard von Bingen saw a b14zing fire incomprehensible inextinguishable with a flame in it the color of the sky

Hildegard von Bingen saw placed beneath her fuet the whole machine of the world as if it were a wheel She saw herself phced

above it her eyes of contemplation magnetized towards the incomprehensible Beatrice of Nazareth I saw the eyes I do not know if I was asleep or awake Angela of Foligno kind of sunlit winged being like a childs head beneath two little wings Abbess Thaisia laquobullbull round patterns small circles would expand and eventually dissipate only to be followed by other small

circles of light Philip St Romain an extraordinary circle of gold light pulsating against a deep violet background There were

always four or fille As soon as one would fode another would appear Philip St Romain

middotItalics added to mark words referring to (l) rings appearing in sets of four (2) amorphous shapes such as clouds or flames (3) circular or eye-like shapes (4) colors from the center of the visible spectrum (gold yellow yellow-green green bluish green) and (5) colors from the lower end of rhe visible spectrum (blue purple violet)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 124

cell membranes (Vm) has already begun to drop (hyperpolarize) in the thalamic reticular nucleus (RTN) a thin sheath of GABAnergic inhibitory neurons that acts as a pacemaker When the Vm of RTN cell membranes drops to approximately V m -60 millivolts (mV) RTN cells stop firing single spikes which are associated with waking states and instead begin firing highshyamplitude 7-14 Hertz (Hz) spike-bursts These bursts wax and wane over 1 to 3 seconds-hence the name spindle -and recur at 3 to 10 seconds Spindle volleys are relayed across the cortical mantle by thalamocortical (TC) sensory relay cells In human studies the primary criterion for onset of the first fullyshyestablished episode of NREMS or stage 2 sleep is the presence of globalized spindles in the cortical EEG

When spindle bursts from the RTN stimulate TC cells to fire in synchrony this synchronous bursting pattern overwhelms the normal capacity of TC cells to relay afferent sensory signals The loss of consciousness at the onset of stage 2 NREMS is thought to be caused by this blocking effect 21

While the RTN is firing spindle bursts through the thalamus another process is activated in the cortex large numbers of cells across the cortical mantle begin to oscillate at a very low frequency laquo 1 Hz)

The cortical slow rhythm referred back to the thalamus via corticothalamic circuits intensifies the hyperpolarizing effect of the RTN spindle bursts on TC cell membranes When V m -75 mV the TC cells begin to generate their own intrinsic calcium currents which further increases hyperpolarization At V m -90 mV the RTN neurons stop firing spindle bursts The TC cells continue to fire low-threshold calcium spikes in patterns which are controlled by the cortical slow rhythm The interaction of these two oscillations generates the delta waves (1 to 4 Hz) which are associated with stage 2 NREMS

In a study of sleep rhythms using the cortical EEG Uchida Atsumi and Kojima found that the mean number of spindles required to induce delta wave activity (that is to induce Vm = -90 mY) is 478 plusmn 162 spindles (from 3 to 7 spindles)22 The mean number of spindles in a volley remains the same for a single individual over multiple trials

Based on the consensus scenario for generation of NREMS we can predict that a phosphene image generated as an epiphenomenon of a thalamic spindle

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 125

Table II Dara show rhe degree of correspondance berween rhe pulse panerns of rhalamic spindles based on intracellular research and rhe sparioremporal panerns of receding annuli phosphenes induced by rhe author using a rechnique of self-hypnosis

Receding annuli phosphenes Thalamic spindle bursrs

Mean number of signals 4 annuli 487 (plusmn 16) bursrs

Sparial exrension vs Thin band 1 - 3 seconds durarion of signal ( 05 -15 cm)

Periodicity of signals 5 seconds 3 - 10 seconds

Simultaneity in LGNs Yes Yes

Point of entry Peripheral VF Ventral amp lareral LGN

Trajecrory Bilareral concentric Unknown

Rare of flow Cons rant rare Unknown

Signal-ro-noise rario High High (shorr bursrs) (sharp brighr discrere)

Termination of sequence Mrer 4 signals Mrer 487 (plusmn 16) signals

will present the following characteristics (1) a high-definition burst-like signal (2) that recurs within 3 to 10 seconds (3) that follows a trajectory compatible with having entered the LGN from the RTN (4) that has a predictable mean for the individual subject and a range that falls somewhere between 2 to 7 annuli and (5) that the spindles will terminate automatically

The temporal patterns of receding annuli and thalamic spindle bursts are similar Table II illustrates the close match between the timing of receding annuli phosphenes and thalamic spindle bursts The most striking similarities are the mean number of signals required to induce termination (4 annuli versus 487 spindles) and the interval between signals (5 seconds for annuli versus 3shyto-lO seconds for spindle bursts) Neither alpha theta nor beta waves present this kind of stereotyped temporal pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 126

T he spatial features of receding annuli are functions of geniculate anatomy A spindle burst moving through the LGN to the cortex will acquire certain distinctive spatiotemporal characteristics because of the

unique curvilinear and laminar anatomy of the LGN A drawing of a macaque LGN based on a clay model constructed by Le Gros Clark23 is shown in Figure 3 The primate LGN is composed of six sheets of cells or laminae that fold over a central hylus In macaques the hylus rises steeply as it extends rostrocausally forming a high arch at the posterior pole in humans the hylus is much more shallow but the functional anatomy is thought to be essentially

23 24the same in both cases - The geometry of the arch forces each lamina to bend so as to constitute in effect one-half of a conical surface and each lamina with its hemi-conical shape contains visual relay cells representing the contralatshyeral half of the visual field (VF) Operating as a pair the complementary hemishycones of the right and left LGN form the functional equivalent of a single conical surface which represents the entire VE This conical geometry of the paired LGNs means a burst of otherwise formless excitation will acquire a distinctive shape as it propagates through the laminae of the LGN Imagine a horizontal section moving along the surface of a cone from base to apex that moving section forms an annulus that shrinks in diameter as it approaches the apex but retains its annular symmetry throughout its trajectory

Figure 3 also includes drawings that show how Connolly and Van Essen24

converted the 3-dimensional structure of lamina 6 the largest and most dorsal layer into a 2-dimensional map Connolly and Van Essen used data obtained by Malpelli and Baker25 to superimpose a grid that specifies the areas in lamina 6 that contain TC cells representing various degrees of isoeccentricity in the VE We will use this map at a later point to show how the movement of a spindle wave through a pair of LGNs correlates with what appears in the VE

The location of the RTN relative to the LGN is also shown in Figure 3 The RTN spindle pacemaker is a thin sheath of GABAnergic inhibitory cells that extends along the surface of the whole posterior ventral thalamus not just the LGN This extension brings the RTN into close proximity with the portion of the LGN (lateral wing) that protrudes out from the main body of the thalamus Some of RTN wraps around and beneath the ventral edges of the LGN26 The RTN comes closest to the LGN in two areas along the ventral edges of the longest laminae (lamina 6 and 1) and along the edge of the lateral

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 127

DORSAL POLE DORSALPOIEA B

L1 L4 L3 L

DORSAL POlE DORSAL POIE (FOVEA)

G LATERAL WING

25

DORSAL POL (FOVEA)

10 _DIAL

20 WING

~

wing These areas contain TC cells that represent the far periphery of the VE If a spindle burst enters the LGN at locations where laminae are in closest proximity to the RTN-along the ventral edges-then the discharge of TC cells will begin in the most ventral portions of the laminae the regions that represent the far periphery of the VE This matches the phosphene sequence observed by the author

Our hypothesis about how this proximity between RTN and LGN affects the trajectory of spindle waves is illustrated in Figure 4 We propose that it is not possible for the author to observe a thin annulus of phosphene sweeping in from all 3600 of the peripheral VF unless spindle bursts exhibit the following

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 128

Figure 3 [facing page Drawings of primate geniculate anatomy and functional anatomy relevant to the generation ofphosphenes (A) Anterior view ofa macaque monkey LGN based on a clay model reconstruction by Le Gros Clark 23 (B) Posterior view ofthe same model showing 6 laminae folded over a central hylus to form lateral and medial wings with the hylus arching steeply upward near the posterior pole to shape the laminae into layers of hollow half-cones nested together Note that the lateral wing of the LGN is slightly larger than the medial wing so that in situ the lateral wing protrudes out from the main body of the thalamus creating a small knob visible during dissection 26 (C) Schematic drawing of an oblique section through median axis (also adapted from Le Gros Clark13 showing how the laminae fuse together at the anterior pole The afferent ganglion cell axons that form the optic tract (OT) penetrate through the anterior surface to reach their target relay cells in the laminae (D) Drawing of the most dorsal lamina-layer 6--separated from the rest of the LGN The geometric shape is a hollow half-cone so that right and left LGNs placed back-to-back form in effect a single cone Note also the position ofthe RTN shown here as a striped bar relative to lamina 6 The position of the striped bar shows that the RTN makes direct contact with lamina 6 at the edge ofthe lateral wing and also along the ventral edges (E - F) Schematic drawings adapted from Connolly and Van Essen24 that show how a 3-dimensional lamina-lamina 6--can be transformed into a 2-dimensional triangular figure lamina 6 is removed and its wings unfolded (E) creating a slightly asymmetric triangular figure (F) which is adjusted to an oblong shape (G) in order to superimshypose a grid matrix with minimal distortion The grid plots locations of TC cells that represent various isoelevations and isoazimuths in the VF locations derived from the experimental observations published by Malpeli and Baker 25 Note the relatively large amounts of laminar surface allocated to central vision (0 0

- 30 0) as compared

to peripheral vision (30 0 - 80 0)

characteristics (1) Spindle bursts must move simultaneously through both geniculate nuclei This pattern of movement is consistent with anatomical studies in primates that found axonal projections linking the right and left RTNs27-28 and with experimental studies in cats that found spindles appearing simultaneously in both right and left thalami 29 (2) Spindle waves must enter the ventral edges of the LGN first and move ventrodorsally in a highly coherent pattern-moving in effect as a standing wave This pattern of movement is consistent with in vitro experiments using sagittal slices from a ferret LGN where spindle waves originated spontaneously at the edge of a slice in an area which contains cells that represent peripheral vision then propagated toward that area of the slice containing cells that represent central vision in the ferret 3o

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 129

VF

PG BIlateral receptive lleJd of PVN YI(j Inward dmKooflality Adapled

0-- from Mortgr at at (1987)

V1

ibull t bull

RTN t t t t t t 1middot3 SECOlO BURSTS OF 7middot14 HZ SPiKES RECURRNG EVERY 3 10 SECONDS

To our knowledge the LGN is the only anatomical structure in the visual system that has the capacity of passively forcing a wave of excitation to flow across a conical surface thereby generating the sensation of a phosphene annulus that retains its symmetry as it shrinks in diameter The retina has a circular anatomy but it is not likely that the mechanical deformation of the retina would produce a wave that began simultaneously in all 3600 of the retinal rim nor that the symmetry of annular wave would be preserved as it flows inward toward the foveal region

The hypothesis presented here-that there is a structure in the visual system that imprints a conical shape on standing waves that move through it-explains

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 130

Figure 4 facing page Schematic drawing of contemporaneous events in selected regions of the visual processing hierarchy (A) The left and right RTNs fire spindle bursts simultaneously (B) The bursts pass through the right and left geniculate laminae as standing waves of depolarization entering from the ventral edges and moving ventrodorsally in parallel In order for the phosphene annulus to appear to be flowing at a constant rate the spindle wave flowing through the LCN must expand in width as it ascends ventrodorsally so that by the time the fill-in disk appears-when the center 30deg of the VF is covered by the phosphene annulus-the spindle wave must have expanded enough to activate relay cells in the most dorsal 50 of lamina 6 (C) Signals representing two complementary hemi-annuli are kept separate in the primary visual cortices (area VI) (D) Signals representing the two hemi-annuli are integrated into signals of a single annulus when they reach area PC in the posterior parietal cortex where the receptive fields of single parietal visual neurons have the capacity to register bilateral signals that exhibit opponent vector movement (that is signals converging from opposite directions along the central axes-as if an object were moving away from the viewer)46 Neurons in area PC also integrate wavelength (color) signals from the extrastriate visual pathway with signals about brightness motion and depth from the parietal visual pathway to compose a representation of an object in space-in this case of an annulus that appears to recede 32

the authors experience during MRI when he observed a continuous succession of receding annuli every 2 seconds in this view the energy of the electroshymagnetic bombardment when released during precessional relaxation flows through the geniculate laminae in the same way that the RTN spindle bursts do that is as a standing wave and thus the visual epiphenomenon is the same in both cases if the subject keeps the eyes focused straight ahead and the attention fixated In a study of phosphenes evoked by electricity in conjunction with hallucinogenic drugs Knoll Kugler Hofer and Lawder found that each subject sees specific kinds of phosphene at different frequencies and that these frequency-specific images are stable enough to be reproduced after six months31

They conclude that the tunability of the electrical stimulation frequenshycies within the EEG range to various definable phosphenes requires the existence of a resonance system One mechanism contributing to that resonance system may be the functional anatomy of the LGN

The colors of receding annuli as functions of geniculate laminar anatomy The colors of receding annuli phosphenes are consistent with the patterns of discharge spindle waves can be expected to stimulate as they move through

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 131

geniculate laminae As shown in Figure 5 the six laminae differ (1) in the types of wavelength signals relayed (2) in physical size and (3) in the area of the VF represented 24-25 Only 4 out of 6 laminae Cparvocellular layers 3shy6) contain TC cells that relay wavelength signals the other 2 laminae (magnocellular layers 1 and 2) do not encode wavelength Among parvocelshylular laminae only lamina 6 the longest and most dorsal layer contains TC cells that can represent the far periphery of the VF (from 800 to 50deg of isoeccenshytdeity) therefore when the spindle wave enters the peripheral VF only those wavelengths relayed by lamina 6 will participate in composing a cortical lightness record (See Zeki)32

I n lamina 6 ganglion cell axons arriving from the retina carry two kinds of wavelength signals (1) center-ON signals from medium-wavelength cones (M-cone center-ON) and long-wavelength cones (L-cone centershy

ON)33-35 Using the cone spectral sensitivity curves (adapted from Marks et al 36) we average the wavelengths that elicit maximal responses for M-cones (535 nanometers) and L-cones (520 nm) which yields a mean wavelength value of 550 nm In humans this wavelength generates a sensation of green or yellowshygreen the sensation observed by the author

As the spindle burst moves ventrodorsally it reaches the dorsal areas in the geniculate laminae which contain TC cells representing the central 0deg to 20deg of isoeccentrieity in the VE All 4 parvocellular laminae have TC cells which are potentially capable of representing this central region of vision but the authors observation that the color of the filling-in disk changed from green to blue implies that in the early years of phosphene induction the spindle wave must have remained close to the surface of the LGN stimulating only laminae 5 and 6 which generates a sensation of yellow-green When the fill-in disk was observed to change color from green to blue the spindle wave must have been rechanneled so that it began to penetrate below laminae 5 and 6 and to activate laminae 3 and 4 the only laminae that relay blue-sensitive signals (Sshycone center-ON signals)3 In light of the authors MRI experience it seems likely that a spindle wave requires a minimum of 2 seconds to reach the blueshysensitive cells of laminae 4 therefore during MRI when the receding annuli disappeared after 2 seconds half the normal duration the fill-disk had a green color even though it had long since change to blue in other induction settings with a 4-second trajectory

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 132

A REPRESENTATION OF THE VISUAL FIELD IN EACH LAMINA

orooqUtftc O-u OCIJ1SALfIOLI (I01flAj

0

10

20

30

40 n50 Of

60

70

20 loO 1Mgr_ II~ o UIpoundAS65 mn1MY-o actlvncL ~~~r

Jll-COMcetlImiddot~

II LAYERSU 3 GatQYancetl~ (1) ucon ceom-oyenF (2)l~cen()FF 3) ~ cenloH

II~ cng1loqctWIIIfNla

iICINe -- (t81Otdb1t1d~OH (2)~

80

B CONE SPECTRAL SENSITIVITY CURVES

S-COHS

WAVIlLllNG1llS OF UGHT IH NANOMllTERS (NM)

Figure 5 Phosphene color as a function of ganglion cell distribution in parvocellular laminae (Aj Schematic drawing ofthe proportion ofthe VF represented in each laminae The proportions shown here are based on the work of Connolly and Van Essen24 The

far periphery of vision (50 0 to 80 0 of isoeccentricity) is represented in only two laminae-laminae 1 and 6-and of these two only lamina 6 is a parvocelLular lamina capable ofencoding wavelength signals Therefore only those wavelengths relayed by lamina 6 will participate in forming a cortical lighmess record for the far periphery of the VP (B) Cone spectral sensitivity curves (adapted from Marks et al)36 Using these cone sensitivity curves we can estimate the sensation stimulated by a spindle wave moving through lamina 6 by averaging the wavelengths that elicit maximal responses for M-cones (535 nanomeshyters) and L-cones (520 nm) which yields a mean wavelength value of550 nm In humans this generates a sensation of green or yellow-green the sensation observed by the author when the receding annulus enters at the far periphery of the VP For a calculation of the cortical lightness record when a spindle wave moves through 20deg to 0deg ofthe VF stimulating all 4 parvocelfular laminae see the text and Figure 6

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 133

Once the spindle wave penetrates to laminae 3 and 4 it may activate all 4 parvocellular laminae stimulating TC cells to send contradictory wavelength signals for the same retinotopic location the signals sent from laminae 4 and 3 will encode blue light (S-cone center-ON plus M-cone center-OFF and Lshycone center-OFF) while the signals sent from laminae 5 and 6 encode yellowshygreen light (M-cone center-ON plus L-cone center-ON) This kind of contrashydiction does not occur in normal retina-based perception where light energy striking the retina is structured by the retinas center-surround and colorshyopponent organization to encode only one set of wavelength signals for each spatial locus 32 In Figure 6 we estimate the cortical lightness record that results when contradictory wavelength signals compete to be represented in consciousshyness Our calculations suggest that the outcome will be a mean wavelength which in humans elicits a dark blue or violet sensation

PART II AMORPHOUS PHOSPHENES amp THALAMIC DELTA ACTMTY

M echanisms controlling the transition from spindle bursts to delta activity In the consensus scenario for the generation of NREMS16-20 we noted that the RTN shifts to firing spindle bursts

when polarization of thalamic cell membranes drops to V m = - 60 mV At the same time cortical cells begin oscillating with a synchronous slow rhythm laquo 1 Hz) Both processes further decrease the Vm of TC cell membranes When Vm = - 75 mY TC cells begin to generate their own intrinsic calcium currents which also decreases V m At V m = - 90 mV RTN neurons stop firing spindle bursts At the same time the TC cells begin firing low-threshold calcium spikes in alternation with after-hyperpolarizations (LTS-AHP) Because sensory relay neurons in the LGN are not linked to one another by locally projecting axons the firing of one TC cell does not excite its neighbor However a lack of local connectivity does not mean that TC cells occupying the same laminae release their AHP-LTS calcium spikes in a random distribshyution rather spikes are released simultaneously by groups of cells in synchrony with the advent of the cortical slow wave In effect the distribution of LTSshyAHP spikes firing in the LGN is determined by the spatial propagation of the cortical slow wave Thus the delta wave (1 to 4 Hz) activity detected by cortical EEG during NREMS is a product of the interaction between the AHP-LTS calcium spikes released by TC cells and the cortical slow rhythm

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 134

CORTICAL PROCESSING OF CONTRADICTORY

WAVELENGTH SIGNALS

KEY _ Cells firing

cJ Cononol firing

Assume that as a spind6e wave moves through the LGNlt fires simultaneously aU the TC cells that represent a particular reUnoshytopic locus (x y) in each of the six laminae As a result cortical cells engaged In the higher level processing of visual signals will receive more wavelength signals representing retina locus (x y) than are generated by normal perception laquo and some of these afferent wavelength signals may contradict other signals arriving simultaneously

CORTICAL LIGHTNESS RECORD SlgnalSell

Intemal contradictions not congruent wilt pre

SmiddotON eristing neuron neta

s bullbull M-ON LmiddotON

3 bullbull M-OFF + L-OFF

a-ON 12

ROD-ON

No Internal eonlradlemiddot

--------1I =~8b~~~~~~~t signals

3+4

~ --OFF Excludes 6 Of 7 $J9n18

1+2 B-ON I

IWmiddotHmiddotI Signal Sell

1111111 No Intern1 conlrfldlcshy lion

Exelvdta 4 out of 7 efshy

bullbullbull bullbullbull ferant signals

No Intern1 contradic_ tionnee S-ON BshyOH and ROO-ON can all be coacllve at low lImlnance levels nef Ihe rod-eone break

ExchJde$ only 2 Ollt of 7 afferent signals

Figure 6 Selection of competing wavelength signals based on neuronal group selection This thought experiment is based on Edelman sconcept ofneuronal group selection 73 We assume that all possible combinations ofsignals will form sets and that all signal-sets will compete to make the most efficient match with pre-existing neuromd networks that have been forged over years ofnorma reti1U1-based perception We also assume that pre-existing neural networks are most likely to expedite those sets that satisfY 2 criteriI (J) the signals in a set do not contradict each other and (2) fower signals are excluded than in the other sets that satisfY the first criterion In our analysis Set 4 wins the competition because it does not contain internal contradictions and excludes fower signals (2 out of 7) than Set 3 excludes (4 out of7) It is not an internal contradiction that Set 4 contains both rods and cone Signtlls in normal retina-based perception when luminance levels approach the rod-cone break S-cone center-ON receptors send signas as do rod receptors and there is even evidence that rod activity may actually drive S-cone activity even after luminance levels foIl below the rod-cone break74 To calculate the cortical lightness record for Set 4 we average the wavelength that elicits maximal responses foom rods (511 nm) and for Sshycones (430 nm) which yields a mean wavelength of 470 nm which in humans results in a dark-blue or violet sensation

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 135

The cortical slow rhythm is an example of a generic pattern of neuronal excitashytion that occurs in large networks of neurons linked by local projections A recent experiment by Maeda Robinson and Kwana38 shows that networks of locally-connected neurons spontaneously generate periodic synchronized bursts of calcium transients that propagate across the network in an expanding spatial wave a pattern that represents a stable mode of firing towards which these neuronal networks relax following perturbations for example by electronic stimulation or by drugs Understanding the characteristics of these waves is an important prerequisite to understanding the mechanisms that produce the amorphous phosphene images as a visual epiphenomenon

To study the spontaneous periodic synchronized bursts the researchers prepared cultures of dissociated cortical neurons and allowed them to mature for several days in vitro (DIV) After 3 to 4 DIV when concenshy

trations of extracellular magnesium were low electrodes began to detect spontaneous synchronized bursts of low frequency calcium transients (between 01 and 1 Hz) that originated in different locations on the sheet every 10 to 20 seconds and spread across the sheet of cells at a relatively slow speed averaging 50 mmsecond The researchers could not predict where a wave would originate or where it would expand rather the initiation and expansion of waves was generated by spatial and temporal summation of a continuous random background of synaptic inputs including miniature spontaneous synaptic events but the pattern was not random since waves propagated sequentially from electrode to electrode as each local group of neurons charges up its neighboring nontefractory areas rather than in a random sequence of regions38

The excitability of the cells in the sheet determines the probability first that there will be a synchronous burst and second that it will spread in a particshyular direction Cells become more excitable as the cultures mature which means the refractory intervals between successive bursts were much shorter in mature cultures (gt 30 DIV) than in early cultures laquo 7 DIV) Some cells became so insensitive to inhibition that they continued to fire bursts even when extracellular concentrations of magnesium were relatively high Finally there were refractory periods of 5 to 10 seconds during which no bursts occurred even when an electrical stimulus was applied This refractory interval for cultured networks is slightly longer than the refractory interval observed of the cortical slow wave in vivo which 25 to 4 seconds 18- 19

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 136

Based on the observations about cortical slow waves we can predict that phosphenes generated as epiphenomena of delta wave activity will present the following signal characteristics (1) signals that appear at unpredictable locations in the VF (2) signals that expand and diverge asymmetrically following unpredictable trajectories which may encompass large areas of the VF (3) signals that move relatively slowly (50 mmsec) (4) signals that recur with a period of 2 to 4 seconds reflecting entrainment by the cortical slow wave (5) signals that do not terminate automatically after a predictable number of cycles

The spatial patterns of phosphene mists and thalamic delta waves are similar The spatiotemporal characteristics of amorphous phosphenes match the pattern of wave propagation associated with periodic spontashy

neous synchronized bursts in large neuron networks the amorphous phosphenes enter the visual field at unpredictable locations expand and diverge asymmetrically with a slow steady rate of flow follow trajectories that are unpredictable and exhibit a refractory interval The amorphous mists do appear to have a periodicity although the author is unable to sustain the vision while also counting the seconds therefore he is unable to determine if it compares to the period of the cortical slow wave (25 to 4 seconds) but his impression is that it feels roughly the same as as with receding annuli which recur at 5 seconds Also the refractory interval feels as if it decreases as the induction session is extended These similarities suggest that the amorphous phosphenes are generated by stage 2 NREMS delta wave activity which is an activity governed by the reverberation of the cortical slow wave in thalamoshycorticothalamic circuits The cortical slow wave is referred to the LGN where it modulates the firing of visual relay cells in the laminae and since relay cells do not have local dendritic connections the expansion of a wave of depolarshyizations moving from one relay cell to the next across in the laminar surface will mirror at least in part the expansion of the cortical wave that is spreading contemporaneously through locally-connected cortical cells

PART III RETENTION OF CONSCIOUSNESS

In a normal transition to NREMS the volley of synchronous spindle bursts that marks the onset of stage 2 NREMS overwhelms the normal firing pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 137

of thalamocortical cells preventing their relay of afferent sensory signals and inducing a loss of consciousness21 But the loss of consciousness cannot be timed precisely using cortical EEG the thalamus is too remote for the onset of spindling to be reliably detected by scalp electrodes39 In experiments with cats where electrodes could be implanted in the thalamus researchers found that spindling often reached peak levels of activity in the thalamus-a level of activity consonant with stage 2 NREMS-at a time when the cortical EEG was still showing intermittent desynchronizations a pattern characteristic of the drowsy stage 1 transition not a fully-established stage 2 NREMS episode4o

In other words there is a short period of time in which the synchronous rhythms of stage 2 NREMS are installed in the thalamus but not in the cortex where cortical neurons continue to depolarize in response to afferent sensory signals

T his finding suggests a possible explanation for the authors ability to retain consciousness while spindle bursts are sweeping through the LGN if he is able to extend the duration of this time lag between

the onset of spindling in the thalamus and spindling in the cortex if he is able to stimulate the visual cortices in such a way that they continue to depolarize then he may be able to keep on processing visual signals-to remain visually aware-even after the non-visual thalamus and non-visual cortex become entrained by synchronous sleep rhythms The authors induction technique includes several behaviors which are known to enhance the responsiveness of visual neurons-eye movements attentive fixation and an attitude of expectancy

Effects of eye movements and attention on the LGN Sustained convergence causes periorbital proprioceptors to send excitatory feedback directly to the LGN41 Also convergence further enhances the excitability of geniculate cells by stimulating the superior collicus (SC) which sends its own excitatory signals to the LGN42-43 These signals from the SC are known to selectively enhance the excitability of visual relay cells that represent the periphery of vision44 We know in the authors case that the SC is being stimulated because he is able to keep on fixating an ability which would normally be lost during the transishytion to NREMS45 The ability to fixate can be retained however if the SC is stimulated (even if stimulated during NREMS)46

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 138

Effects of eye movement attention and expectancy on the primary visual cortex The PET study of mental imagery by Kosslyn et al 3 showed that even a baseline resting state of relaxed immobile expectancy can generate signifishycant increases in neuronal activity in the primary visual cortices Further increases can be induced by sustained eye movements

A sustained convergence will release a stream of ponto-geniculo-occipital (PGO) waves These PGO waves called eye movement potentials or EMPs last only as long as the eye movement1747 whereas the PGO waves associated with rapid-eye-movement sleep (REMS) fire continually for the duration of the REMS episode Both REMS-related PGO waves and EMPs have the same desynchronizing effect on the visual pathways they move through the LGN depolarizing the thalamocortical cells which relay the signals to cortical neurons The responsivity of neurons in the primary visual cortices is enhanced by the stimulation of PGO waves 1747-49 If the passage of EMPs causes the genicushylate relay cells and their cortical targets to depolarize regularly then a volley of 4 spindle bursts moving through the same pathways will register as just another series of depolarizations in effect the spindle bursts are processed by the visual system as if they were sensory signals sent from the retina rather than an event stimulated by endogenous mechanisms

T he impact of eye movements and ftxation on the parietal visual cortex Convergence and attentive fixation will also enhance the responsiveness of light-sensitive parietal visual neurons (PVNs) in area PG of the

posterior parietal cortex 50 In experiments where monkeys are trained to fix their attention on a screen-and to keep on fixating even if no targets appearshythe excitability of these light-sensitive PVNs increases by as much as 350 51

52-53Responsiveness is also facilitated by the angle of gaze Also area PG is the first region in the visual pathways containing individual neurons with the capacity to respond to large bilateral stimuli moving in opposite directions along the central meridians of vision (opponent vector motion) 853-55 Facilitation of PVNs in area PG has the effect of sensitizing the subject to bilateral opponent vector motion and this is especially true if the movement appears in the periphery of the VE 8

Intracortical ampliftcation and feedback to the LGN When PGO waves and signals from the SC arrive in the primary visual cortex they may be relatively weak however weak signals can be amplified by reverberating in large networks

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 139

of cortical cells linked by local projection 56 There are nine times as many excitatory links among cortical cells as there are projections from the visual cortex to the LGN an imbalance which suggests leads Suarez Koch and Douglas to propose that geniculate input provides only a minor fraction of the excitatory input the majority originating in neighboring and recurrently connected cortical cells57 If the excitabiliry of cortical neurons is slightly higher than normal then this process of amplification may continue even after the LGN signals that initiated the reverberation are no longer being transmitted by the LGN ( a hysteretic mode of operation) 57

Feedback from hyperexcited cortical neurons will stream back to the LGN via corticogeniculate projections which outnumber geniculocortical projections ten-to-one One effect of this feedback is that the LGN is

able to absorb large amounts of information flowing back from the cortex 58

As signals reverberate back and forth in thalamocorticothalamic circuits a matching process takes place those geniculate relay cells that fire in patterns consistent with the firing patterns of active cortical cells will have their responshysivity enhanced while those geniculate cells that fire in patterns not consistent with cortical cells will be suppressed 59

Preservation of consciousness by selective facilitation of the visual pathways By combining all of the facilitatory effects produced by the authors eye movements and attentive fixation-(l) stimulation of the LGN by feedback from periorbital proprioception both directly and indirectly via the SC (2) the release of PGO waves (EMPs) that facilitate neurons in the LGN and primary visual cortex as they pass (3) the facilitation of the primary visual cortex by a state of relaxed immobile expectancy (4) attentive fixation and angle of gaze that facilitate PVNs in area PG (5) intracortical amplification of signals received from the LGN and (6) corticogeniculate feedback that stimulates the LGN-we delineate a circuit of enhanced excitability that extends from the LGN through the post-geniculate visual heirarchy to area PG where signals are integrated into representations of objects

The hyperexcitability of neurons all along the post-geniculate visual pathways creates conditions in the visual cortices which are similar to those present during EEG-desynchronized states of waking and REMS Therefore neurons in the visual pathways are too excitable to be entrained by synchronous bursting

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 140

patterns when spindle waves move through them instead the spindle bursts stimulate visual neurons to depolarize and then recover as happens in response to afferent sensory signals during waking states It is important to note that for this to occur none of the constituent neuron assemblies is required to perform an abnormal operation the abnormality is a function of the authors intent to activate contemporaneously neuron assemblies that would not normally be co-activated

PART IV HYPNOTIC ANALGESIA

Manipulation of spatial attention as a method for alleviating pain sensations In a theoretical article on the neurophysiology of hypnosis Crawford and Gruzelier60 propose that variations in hypnotizability are function of variability in the efficiency of the frontolimbic (anterior) attentional system in humans high-hypnotizables are better able to sustain focused attention on a task and to ignore extraneous stimuli than are low-hypnotizables

I na related empirical study that compares the use of attention by subjects with high versus low hypnotizability Crawford Brown and Moon61 report that highly hypnotizable persons continue to show physiological reactivity

while cognitively not perceiving the painful stimuli Through disattentional processes they can dissociate themselves from the awareness of pain The authors phosphene induction behaviors-and the cutaneous analgesia he experishyences-appear to involve the same kind of behaviors that is a mobilization of frontolimbic attention used to withdraw attention from external stimuli and to concentrate it on internally-generated phosphene images This suggests the hypothesis that the mechanisms that generate phosphenes might also produce hypnotic analgesia There are several ways that visual signals and pain signals might interact to produce this analgesia

Competition between pain and vision signals for limbic registration The fully-developed sensation of pain requires integration of rwo kinds of informashytion Signals that encode the location and intensity of a noxious stimulus (nociceptive signals) are relayed via the thalamus to the somatosensory cortices which registers only the sensory-discriminative aspects of pain perception62 before reaching consciousness the nociceptive signals must be sent to the limbic

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 141

system where they are linked with signals from long-term memory that encode the affective significance the stimulus has acquired for that individual Studies of brain metabolism show this linking of somatosensory information with limbic associations takes place in the anterior cingulate (CG) and anterior insula62-64

PET studies also show that the anterior CG is activated when subjects shift their spatial attention in response to expectations as to where

66stimuli will next appear65- This is precisely what takes place during the state of immobile expectancy that induces phosphenes Since visual signals and nociceptive signals both require limbic enhancement which is only possible if they get access to the anterior CG there might be conditions in which the two types of afferent sensory signals have to compete for that access In a theoretical article on the mechanisms of attention Posner and Rothbart67

propose that visual signals can interfere with nociceptive signals by blocking access to the anterior CG As behavioral evidence they cite studies showing that when young infants make distress calls they can be distracted by the presentation of a new visual stimulus We have shown the evidence of such control at about three months Orienting to visual events can be employed to quiet or calm negative vocalizations However the distress appears to be maintained and reappears when the infants attention to the stimulus is reduced Caregivers also report the use or visual orienting to block overt manifestations of distress at about this age 67

The effects of disattention on the somatosensory cortices If there is a competition between visual signals and nociceptive signals for access to the anterior CG it is likely that the competition will be affected by the relative volume of signals received A recent study suggests that focusing attention on internally-generated visual stimuli may reduce the number of nociceptive signals relayed by the somatosensory cortices Drevets Burton Videen Snyder Simpson and Raichle68 have shown that the mere anticipation of a touch at a specific cutaneous site increases the flow of blood to those cortical somatosenshysory neurons that are linked with that site where touch is expected and decreases the flow of blood to neurons linked with sites where touch is not expected In this experiment the researchers designated touch as the behaviorally significant sensory stimulus but their findings suggest that the outcome could be reversed if the instructions were reversed if subjects were

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page J42

instructed to direct attention away from a cutaneous site where a noxious stimulus was being applied if they were instructed to relax close their eyes and concentrate on the play of phosphenes in the visual field as the behaviorally significant sensory stimulus then it would be reasonable to expect that the flow of blood would decrease to the somatosensory neurons linked with the cutaneous stimulus and that the flow of blood would increase to the visual cortices The decrease in blood flow to somatosensory neurons implies less neuronal activity which implies that fewer signals are being sent forward to the anterior CG than would have been sent if instead the subject were treating the touch as the behaviorally significant sensory stimulus If fewer pain signals arrive at the anterior it is reasonable to infer that the conscious experience of pain will be muted by the diversion of attention to internal visual stimuli

Differential impact of sleep rhythms in the visual and nonvisual thalamus There is another mechanism that might also contribute to the analgesic effect of inducing sleep rhythms PET studies show that

the thalamus is involved in the relay of nociceptive signals to the cortex63 although some confusion remains about which kinds of signals are relayed by which subregions in the thalamus62 One thalamic site clearly identified by anatomical studies as a relay for nociceptive signals is the ventroposterior lateral nucleus (VPL)69 If synchronous sleep rhythms are active in the thalamus we can reasonably expect that the VPL will itself be entrained by synchronous oscillations and that it will relay the sleep rhythms to somatosensory cortices Relay neurons in the VPL are not stimulated by feedback from eye movements and fixation as are relay neurons in the LGN which suggests that sleep rhythms may impede the relay of nociceptive signals via the VPL but not the relay of visual signals via the LGN

Brain waves associated with anesthesia and NREMS The hypothesis presented here-that consciousness can be preserved despite the presence of NREMS activity-is consistent with a recent report that the kinds of fast brain waves which are normally associated with conscious states are also present during NREMS and anesthesia two states which were thought to involve minimal brain activityJo Another recent study found that there is a close resemblance between the slow brain waves that appear during NREMS and those that appear during certain types of anesthesia71

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 143

bull bull bull

CONCLUSION

In this paper we have presented evidence supporting the hypothesis that phosphene images can be generated as an epiphenomena of thalamic spindle bursts and delta wave activity normally associated with NREMS The prereqshyuisites for inducing these sleep rhythm phosphenes are relaxed immobile expectancy sustained convergence and attentive fixation of an undifferentiated visual field Our hypothesis provides a necessary and sufficient explanation for the authors induction of phosphenes and perhaps also for the generation of phosphenes reported to appear spontaneously during the drowsy transition to sleep (hypnagogic states) during sensory deprivation or during certain kinds of prayer or meditation all of which involve a similar state of relaxed immobile expectancyJ2

CORRESPONDENCE Philip T Nicholson bull 52 Norfolk Road bull Chestnut Hill MA 02167

REFERENCES amp NOTES

1 M 1 Posner Modulation by Instruction Nature 373 (1995) pp 198-199 2 J Reissenweber E David amp M pfotenhauer Investigations of Psychological Aspects of

the Perception of Magnetophosphenes and Electrophosphenes Biomedizinische Tecknik 373 (1992) pp 42-45

3 S M Kosslyn W L Thompson 1 J Kim amp N M Alpert Topographical Representations of Mental Images in Primary Visual Cortex Nature 378 (I995) pp 496-498

4 P E Roland amp B Gulyas Visual Memory Visual Imagery and Visual Recognition of Large Field Patterns by the Human Brain Functional Anatomy by Positron Emission Tomography Cerebral Cortex 51 (1995) pp 79-93

5 H Benson The Relaxation Response (Morrow New York NY 1975) 6 ] H Schultz amp W Luthe Autogenic Training a Physiological Approach to Psychotherapy

(Grune amp Stratton New York NY 1969) 7 E Jacobson Progressive Relaxation (University of Chicago Press Chicago IL 1938) 8 M A Steinmetz BC Motter C] DuffY amp V B Mountcastle Functional Properties

of Parietal Visual Neurons Radial Organization of Directionalities Within the Visual Field Journal ofNeuroscience 71 (1987) pp 177-191

9 R R Edelman Magnetic Resonance Imaging of the Nervous System Discussions in Neuroscience 71 Elsevier Science Amsterdam (I990) also J H Newhouse amp ] I Wiener Understanding MRI 1st Ed (Little Brown Boston MA 1991)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 144

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

Figure 2 [focing page Schematic drawings of of amorphous expanding phosphenes (A) Brief randomly-dispersed localized pulses These phosphenes are the first to appear after the receding annuli They coalesce at unpredictable locations in the IF expand asymmetrically for a second or two then dissipate into eigengrau before there is time to extend very for beyond their locus of origin (B) Periodic unidirectional amorphous expanding waves These phosphene waves enter the periphery ofvision from one hemifield presenting as a loosely-defined crescent (hemi-annular) cloud that mirrors the curvature of the peripheral rim The leading edge of the wave expands and flows across the vertical meridian into the opposite hemified swirling around the periphery curling inward and merging while at the same time the trailing edge ofphosphene dissipates rapidly in those regions over which the wave has already passed like mist or smoke evaporating in air The author is unable to time these waves but their duration fiels roughly the same as for receding annuli ie about 4 seconds Waves appear one after another in a cluster with a refractory period between clusters during which no waves appear After a prolonged session ofself-hypnosis the phosphene may not completely dissipate between successive waves in which case the residual phosphene accumulates in a vaguely-circular cloud shape with a small area its center that undergoes continual perturbation the phosphene pulls back leaving a small Mrk circle at the center of the cloud then fills back in then pulls away again ebbing and flowing in like manner until the cloud dissipates At this stage the image resembles an eye with a phosphene iris and a dark inner pupil (C) Twoshytone phosphene During a prolonged session the phosphene at the very center of the amorphous cloud becomes much brighter more fine-grained almost opaque with highly saturated color When a hole (pupil) appears in the center ofthe cloud forming an eyeshyimage the brighter phosphene becomes a thin bright rim lining the Mrk hole from this bright inner rim tiny promontories ofbright phosphene flare out into the Mrk hole twist and coil and collide with other flares forming webs and momentarily filling-in the Mrk hole or receding back into the rim The two-toned phosphene does not only appear in conjunction with the eye-shape clouds it also manifests at the center ofa variety ofelusive ever-changing shapes It is always restricted to the area offoveal vision

(B) PERIODIC UNIDIRECTIONAL AMORPHOUS WAVES These phosphene waves sweep in from one hemifield as shown in Figure 2(B) Often the wave has a vaguely crescent shape at the outset that conforms to the concave curvature of the peripheral VF then the crescent shape gives way as the wave expands rapidly in divergent directions flowing smoothly across the vertical meridian to envelop those regions of the VF that have not yet been illuminated As the leading edge of the wave expands the rear edges are already beginning to dissipate The swirling movement and the contraction of outer boundaries leaves a cloud of phosphene near the center of the VE This cloud may dissipate rapidly or it may persist for several seconds during which a pertur-

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 119

bation takes place at the center of the cloud the phosphene ebbs away from this region leaving a tiny dark hole then the phosphene fills back in then it ebbs and fills again-a fluctuation that continues as long as the phosphene cloud is visible During the perturbations the phosphene vaguely resembles the iris of a human eye with an interior dark space as its pupil This eyeshyimage is seldom symmetrical and its boundaries are always changing

(c) TWO-TONE PHOSPHENE When the phosphenes are induced over a prolonged period of time the phosphene in the central region representing foveal vision presents a more intensely bright more opaque (finely-grained) character than the rest of the cloud as shown in Figure 2(C) When this brilliant opaque phosphene appears as part of an eye-image it forms a thin rim surrounding the pupiL From this rim flares jut out into the dark pupil space coil about merge or recede back into the rim

The periodic unidirectional amorphous waves do not terminate after a stereoshytyped sequence they can be evoked over prolonged rime periods if the autohypshynotic behaviors are maintained The author is unable to retain the vision of these amorphous waves while simultaneously counting the number of seconds elapsed it is his impression however that the duration of amorphous expanding waves feels about the same as for receding annuli that is a duration of about 4 seconds per wave The amorphous waves usually appear in clusters followed by a refractory interval during which no phosphenes appear even if induction behaviors are sustained

PHOSPHENES SUPERIMPOSED ON ExTERNAL OBJECTS

The author can observe amorphous phosphene images with his eyes open if he is in a room dark enough that colors cannot be distinguished or if he is

in a lighted room but one where he can keep his eyes diffusely focused on a relatively undifferentiated surface such as a wall or ceiling with a light and uniform color and no distracting decorative adornments In open-eye viewings phosphenes appear as faint translucent waves of yellow-green mist

superimposed over the surface or in the dark space that fills the darkened room If the author attempts to focus on the features of external objects the phosphenes disappear

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 120

RECEDING ANNuLI EVOKED BY MAGNETIC REsONANCE IMAGING (MRI)

A s a patient undergoing an MRI scan the author observed an unusual sequence of receding annuli He was not relaxed as in a normal induction but rather anxious about his medical condition and about

being confined in the narrow MRI tube To keep calm he concentrated on breathing slowly and stared straight ahead While the sound of MRI machine was audible the author observed a stream of receding annuli that differed from the usual sequence (self-induced and hypnagogic) in three ways (I) the MRI annuli did not terminate at 4 cycles but continued for as long as the author kept his attention focused (2) the MRI annuli were only yellowshygreen in color even though in other inductions the fill-in disk had already changed from green to blue and (3) MRI annuli completed their trajectoshyries in half the normal time disappearing in 2 seconds instead of 4 An interval of 2 seconds between radio pulses is often selected as optimal interval for capture of the signals emitted by hyperexcited atoms in the subjects body

10during the precessional relaxation 9- These observations suggest that energy released in the wake of the radio bombardment during MRI moves through the LGN as a standing wave in the same way that spindle bursts move but that the 2-second duration of the MRI wave is not long enough to activate the neurons that generate a blue sensation

THE ANESTHETIC EFFECT ASSOCIATED WITH SELF-INDUCED

PHOSPHENES

On several occasions the author has preferred to undergo minor surgery without local anesthetic and to rely instead on autohypnotic analgesia-for example during extraction of an infected abscess from the back during laser surgery to

remove keloids and during the filllng of dental caries His experience on a recent occasion when a dentist had to abrade the surface of six teeth with damaged enamel in order to create a strong bonding surface are worth describing here because the experience implies that spindle waves can be induced even during a state of high physiological arousal For this appointshyment the author arrived in the office too late to hypnotize himself in advance

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 121

so he had to begin the normal induction procedures after the dental work was already underway

A s the dentist worked on the first tooth the author experienced apprehension sharp sensations of pain and an involuntary tensing of the large muscles of the body with each application of the drill As

the author kept his eyes converged and his attention focused on the center of the visual field the involuntary tensing in response to pain alternated with a precipitous relaxing of those same muscles immediately after the stimulus With the repeated relaxation came a sense of relief and of letting go that amelioshyrated the pain The pain-driven relaxation was much stronger than the relaxation that normally accompanies the authors self-induction of phosphenes and the alternation of a pain-driven tensing on one hand and the distancing effect of focusing attention on the visual field on the other hand resulted in a rapid dissociation from all external and internal stimuli including a signifishycant amelioration of painful sensations

Most striking is the fact that by the time the dentist reached the third toothshyafter only a few minutes of this pain-driven self-hypnosis-the author saw a normal sequence of 4 receding annuli followed by swirling clouds of amorphous expanding phosphene even though the dentist was still using the drill contemporaneously This experience suggests that thalamic sleep rhythms can be voluntarily induced even when the subjects level of physiological arousal is high

SIMILARITIES WITH ATTENTION-INDUCED PHOSPHENES

REpORTED BY OTHER OBSERVERS

Taxonomies of phosphene images always include examples of simple geometric phosphenes with circular or semi-circular shapes (disks annuli or crescents) as

14well as formless phosphene mists 11 - There are also a number of anecdotal accounts that are relevant for example Friedman an opthamologist who studied entoptic images by introspection describes a similar sequence of annuli induced by sustained inward concentration Circular waves of blue color may be seen in the dark by the dark adapted retina They start at the

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 122

periphery and move inward toward the macula as a concentrically contracting solid circle disappear at the macula and begin again at the peripheryl)

A valuable but often-neglected resource of information about phosphene imagery is presented in the literature of religious mysticism Many mystics reported having seen translucent colored lights while absorbed in prayer or meditation A list of descriptions excerpted from self-reports is presented in Table 1 (These excerpts are representative of phosphene images that appear during states of calm and inward-oriented concentration they do not include images associated with paroxysmal raptures) These phosphene images exhibit a relatively limited set of shapes and colors the shapes are either circular (eg rings disks wheels suns) or formless (eg mists snow smoke) and the colors are usually a variant of either green or blue The phosphene visions of mystics display shapes and colors that are comparable to the images described by the author this and the many similarities in the behaviors used to induce phosphenes suggest that both sets of phosphenes have a common etiology

DISCUSSION

Whether the author uses self-hypnosis to induce phosphenes or experishyences them as hypnagogic images the threshold sequence of receding annuli has the same characteristics In both these

instances the antecedent behaviors involve a state of low physiological arousal combined with mental withdrawal from external stimuli These parallels suggest the hypothesis that phosphene displays are related to sleep-wake transitions

PART I RECEDING ANNULI AND THALAMIC SPINDLES

Mechanisms controlling the transition from waking to NREMS Based on the work of several research teams16-20 a consensus scenario for the generation of NREMS has emerged In this scenario NREMS is the product of three brain rhythms that interact with each other in thalamocorticothalamic circuits During the drowsy transition to sleep which in humans is called stage l NREMS the low voltage activity in the cortical electroencephalograph (EEG) still shows a pattern of intermittent desynchronization The polarization of

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 123

Table I Excerpts from self-reports of light visions by religious mystics

HEBREW MYSTICS the appearance of the wheels was like the gleaming of beryl and the four had the same form

their construction being something like a wheel within a wheel Ezekiel like a dome shining like crystal spread out about their heads And above the dome something

like a rhrone in appearance like sapphire Ezekiel a round Iodder like a full sphere rolling back and forth before him bright blue R Abulafia A glowing light clear brilliance A purple light that absorbs all lights R Moses de Leon

HINDU AND BUDDHIST MYSTICS a perfectly round beautiful deep-blue shape of a size appropriate to the center of a mandala as

if exquisitely painted of extreme c14rity Tsong Khapa a luminous revolving disc studded with lights a lotus flower in full bloom Gopi Krishna both my eyes became cemered When this happened a blue light arose in my eyes like

a candle flame without a wick and stood motionless in the ajna chakra S Muktananda

MUSLIM MYSTICS [like] chandelierssublime lights [like] stars moon or the sun Sharafuddin aI-Maneri its color is deep blue it seems to be an upsurge like water foom a spring Najmoddin Kobra visualize yourself as lying at the bottom of a well [looking up at the light of the opening] and

the well in lively downward movement Najmoddin Kobra the color green is the suprasensory uniting all the suprasensories Alaoddawleh Semnani the light rises in the Sky of the hean taking the form of light-gilling moons Najm Razi

CHRISTIAN MYSTICS his own state at prayer resembles a sapphire it is as clear and bright as the sky Evagrius descending like a bright cloud of mist like a sun round as a circle Simeon Neotheologos saw something in the air near him He did not understand the rype of thing but in some ways

it appeared to have the form of a serpent with many things that shone like eyes although they were not eyes Ignatius of Loyola

the soul puts on a green amilia [cape worn on shoulders beneath armor] John of the Cross [the almilla is like a helmet which] coverS all the senses of the head of the soul It has one

hole rhrough which the eyes may look upwards John of the Cross a round thing about rhe size of a rixdaier all bright and clear with light like a crystal H Hayen I saw a bright light and in this light the figure of a man the color of sapphireblazing with a

gentle glowing fire the three were in one light Hildegard von Bingen saw a b14zing fire incomprehensible inextinguishable with a flame in it the color of the sky

Hildegard von Bingen saw placed beneath her fuet the whole machine of the world as if it were a wheel She saw herself phced

above it her eyes of contemplation magnetized towards the incomprehensible Beatrice of Nazareth I saw the eyes I do not know if I was asleep or awake Angela of Foligno kind of sunlit winged being like a childs head beneath two little wings Abbess Thaisia laquobullbull round patterns small circles would expand and eventually dissipate only to be followed by other small

circles of light Philip St Romain an extraordinary circle of gold light pulsating against a deep violet background There were

always four or fille As soon as one would fode another would appear Philip St Romain

middotItalics added to mark words referring to (l) rings appearing in sets of four (2) amorphous shapes such as clouds or flames (3) circular or eye-like shapes (4) colors from the center of the visible spectrum (gold yellow yellow-green green bluish green) and (5) colors from the lower end of rhe visible spectrum (blue purple violet)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 124

cell membranes (Vm) has already begun to drop (hyperpolarize) in the thalamic reticular nucleus (RTN) a thin sheath of GABAnergic inhibitory neurons that acts as a pacemaker When the Vm of RTN cell membranes drops to approximately V m -60 millivolts (mV) RTN cells stop firing single spikes which are associated with waking states and instead begin firing highshyamplitude 7-14 Hertz (Hz) spike-bursts These bursts wax and wane over 1 to 3 seconds-hence the name spindle -and recur at 3 to 10 seconds Spindle volleys are relayed across the cortical mantle by thalamocortical (TC) sensory relay cells In human studies the primary criterion for onset of the first fullyshyestablished episode of NREMS or stage 2 sleep is the presence of globalized spindles in the cortical EEG

When spindle bursts from the RTN stimulate TC cells to fire in synchrony this synchronous bursting pattern overwhelms the normal capacity of TC cells to relay afferent sensory signals The loss of consciousness at the onset of stage 2 NREMS is thought to be caused by this blocking effect 21

While the RTN is firing spindle bursts through the thalamus another process is activated in the cortex large numbers of cells across the cortical mantle begin to oscillate at a very low frequency laquo 1 Hz)

The cortical slow rhythm referred back to the thalamus via corticothalamic circuits intensifies the hyperpolarizing effect of the RTN spindle bursts on TC cell membranes When V m -75 mV the TC cells begin to generate their own intrinsic calcium currents which further increases hyperpolarization At V m -90 mV the RTN neurons stop firing spindle bursts The TC cells continue to fire low-threshold calcium spikes in patterns which are controlled by the cortical slow rhythm The interaction of these two oscillations generates the delta waves (1 to 4 Hz) which are associated with stage 2 NREMS

In a study of sleep rhythms using the cortical EEG Uchida Atsumi and Kojima found that the mean number of spindles required to induce delta wave activity (that is to induce Vm = -90 mY) is 478 plusmn 162 spindles (from 3 to 7 spindles)22 The mean number of spindles in a volley remains the same for a single individual over multiple trials

Based on the consensus scenario for generation of NREMS we can predict that a phosphene image generated as an epiphenomenon of a thalamic spindle

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 125

Table II Dara show rhe degree of correspondance berween rhe pulse panerns of rhalamic spindles based on intracellular research and rhe sparioremporal panerns of receding annuli phosphenes induced by rhe author using a rechnique of self-hypnosis

Receding annuli phosphenes Thalamic spindle bursrs

Mean number of signals 4 annuli 487 (plusmn 16) bursrs

Sparial exrension vs Thin band 1 - 3 seconds durarion of signal ( 05 -15 cm)

Periodicity of signals 5 seconds 3 - 10 seconds

Simultaneity in LGNs Yes Yes

Point of entry Peripheral VF Ventral amp lareral LGN

Trajecrory Bilareral concentric Unknown

Rare of flow Cons rant rare Unknown

Signal-ro-noise rario High High (shorr bursrs) (sharp brighr discrere)

Termination of sequence Mrer 4 signals Mrer 487 (plusmn 16) signals

will present the following characteristics (1) a high-definition burst-like signal (2) that recurs within 3 to 10 seconds (3) that follows a trajectory compatible with having entered the LGN from the RTN (4) that has a predictable mean for the individual subject and a range that falls somewhere between 2 to 7 annuli and (5) that the spindles will terminate automatically

The temporal patterns of receding annuli and thalamic spindle bursts are similar Table II illustrates the close match between the timing of receding annuli phosphenes and thalamic spindle bursts The most striking similarities are the mean number of signals required to induce termination (4 annuli versus 487 spindles) and the interval between signals (5 seconds for annuli versus 3shyto-lO seconds for spindle bursts) Neither alpha theta nor beta waves present this kind of stereotyped temporal pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 126

T he spatial features of receding annuli are functions of geniculate anatomy A spindle burst moving through the LGN to the cortex will acquire certain distinctive spatiotemporal characteristics because of the

unique curvilinear and laminar anatomy of the LGN A drawing of a macaque LGN based on a clay model constructed by Le Gros Clark23 is shown in Figure 3 The primate LGN is composed of six sheets of cells or laminae that fold over a central hylus In macaques the hylus rises steeply as it extends rostrocausally forming a high arch at the posterior pole in humans the hylus is much more shallow but the functional anatomy is thought to be essentially

23 24the same in both cases - The geometry of the arch forces each lamina to bend so as to constitute in effect one-half of a conical surface and each lamina with its hemi-conical shape contains visual relay cells representing the contralatshyeral half of the visual field (VF) Operating as a pair the complementary hemishycones of the right and left LGN form the functional equivalent of a single conical surface which represents the entire VE This conical geometry of the paired LGNs means a burst of otherwise formless excitation will acquire a distinctive shape as it propagates through the laminae of the LGN Imagine a horizontal section moving along the surface of a cone from base to apex that moving section forms an annulus that shrinks in diameter as it approaches the apex but retains its annular symmetry throughout its trajectory

Figure 3 also includes drawings that show how Connolly and Van Essen24

converted the 3-dimensional structure of lamina 6 the largest and most dorsal layer into a 2-dimensional map Connolly and Van Essen used data obtained by Malpelli and Baker25 to superimpose a grid that specifies the areas in lamina 6 that contain TC cells representing various degrees of isoeccentricity in the VE We will use this map at a later point to show how the movement of a spindle wave through a pair of LGNs correlates with what appears in the VE

The location of the RTN relative to the LGN is also shown in Figure 3 The RTN spindle pacemaker is a thin sheath of GABAnergic inhibitory cells that extends along the surface of the whole posterior ventral thalamus not just the LGN This extension brings the RTN into close proximity with the portion of the LGN (lateral wing) that protrudes out from the main body of the thalamus Some of RTN wraps around and beneath the ventral edges of the LGN26 The RTN comes closest to the LGN in two areas along the ventral edges of the longest laminae (lamina 6 and 1) and along the edge of the lateral

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 127

DORSAL POLE DORSALPOIEA B

L1 L4 L3 L

DORSAL POlE DORSAL POIE (FOVEA)

G LATERAL WING

25

DORSAL POL (FOVEA)

10 _DIAL

20 WING

~

wing These areas contain TC cells that represent the far periphery of the VE If a spindle burst enters the LGN at locations where laminae are in closest proximity to the RTN-along the ventral edges-then the discharge of TC cells will begin in the most ventral portions of the laminae the regions that represent the far periphery of the VE This matches the phosphene sequence observed by the author

Our hypothesis about how this proximity between RTN and LGN affects the trajectory of spindle waves is illustrated in Figure 4 We propose that it is not possible for the author to observe a thin annulus of phosphene sweeping in from all 3600 of the peripheral VF unless spindle bursts exhibit the following

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 128

Figure 3 [facing page Drawings of primate geniculate anatomy and functional anatomy relevant to the generation ofphosphenes (A) Anterior view ofa macaque monkey LGN based on a clay model reconstruction by Le Gros Clark 23 (B) Posterior view ofthe same model showing 6 laminae folded over a central hylus to form lateral and medial wings with the hylus arching steeply upward near the posterior pole to shape the laminae into layers of hollow half-cones nested together Note that the lateral wing of the LGN is slightly larger than the medial wing so that in situ the lateral wing protrudes out from the main body of the thalamus creating a small knob visible during dissection 26 (C) Schematic drawing of an oblique section through median axis (also adapted from Le Gros Clark13 showing how the laminae fuse together at the anterior pole The afferent ganglion cell axons that form the optic tract (OT) penetrate through the anterior surface to reach their target relay cells in the laminae (D) Drawing of the most dorsal lamina-layer 6--separated from the rest of the LGN The geometric shape is a hollow half-cone so that right and left LGNs placed back-to-back form in effect a single cone Note also the position ofthe RTN shown here as a striped bar relative to lamina 6 The position of the striped bar shows that the RTN makes direct contact with lamina 6 at the edge ofthe lateral wing and also along the ventral edges (E - F) Schematic drawings adapted from Connolly and Van Essen24 that show how a 3-dimensional lamina-lamina 6--can be transformed into a 2-dimensional triangular figure lamina 6 is removed and its wings unfolded (E) creating a slightly asymmetric triangular figure (F) which is adjusted to an oblong shape (G) in order to superimshypose a grid matrix with minimal distortion The grid plots locations of TC cells that represent various isoelevations and isoazimuths in the VF locations derived from the experimental observations published by Malpeli and Baker 25 Note the relatively large amounts of laminar surface allocated to central vision (0 0

- 30 0) as compared

to peripheral vision (30 0 - 80 0)

characteristics (1) Spindle bursts must move simultaneously through both geniculate nuclei This pattern of movement is consistent with anatomical studies in primates that found axonal projections linking the right and left RTNs27-28 and with experimental studies in cats that found spindles appearing simultaneously in both right and left thalami 29 (2) Spindle waves must enter the ventral edges of the LGN first and move ventrodorsally in a highly coherent pattern-moving in effect as a standing wave This pattern of movement is consistent with in vitro experiments using sagittal slices from a ferret LGN where spindle waves originated spontaneously at the edge of a slice in an area which contains cells that represent peripheral vision then propagated toward that area of the slice containing cells that represent central vision in the ferret 3o

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 129

VF

PG BIlateral receptive lleJd of PVN YI(j Inward dmKooflality Adapled

0-- from Mortgr at at (1987)

V1

ibull t bull

RTN t t t t t t 1middot3 SECOlO BURSTS OF 7middot14 HZ SPiKES RECURRNG EVERY 3 10 SECONDS

To our knowledge the LGN is the only anatomical structure in the visual system that has the capacity of passively forcing a wave of excitation to flow across a conical surface thereby generating the sensation of a phosphene annulus that retains its symmetry as it shrinks in diameter The retina has a circular anatomy but it is not likely that the mechanical deformation of the retina would produce a wave that began simultaneously in all 3600 of the retinal rim nor that the symmetry of annular wave would be preserved as it flows inward toward the foveal region

The hypothesis presented here-that there is a structure in the visual system that imprints a conical shape on standing waves that move through it-explains

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 130

Figure 4 facing page Schematic drawing of contemporaneous events in selected regions of the visual processing hierarchy (A) The left and right RTNs fire spindle bursts simultaneously (B) The bursts pass through the right and left geniculate laminae as standing waves of depolarization entering from the ventral edges and moving ventrodorsally in parallel In order for the phosphene annulus to appear to be flowing at a constant rate the spindle wave flowing through the LCN must expand in width as it ascends ventrodorsally so that by the time the fill-in disk appears-when the center 30deg of the VF is covered by the phosphene annulus-the spindle wave must have expanded enough to activate relay cells in the most dorsal 50 of lamina 6 (C) Signals representing two complementary hemi-annuli are kept separate in the primary visual cortices (area VI) (D) Signals representing the two hemi-annuli are integrated into signals of a single annulus when they reach area PC in the posterior parietal cortex where the receptive fields of single parietal visual neurons have the capacity to register bilateral signals that exhibit opponent vector movement (that is signals converging from opposite directions along the central axes-as if an object were moving away from the viewer)46 Neurons in area PC also integrate wavelength (color) signals from the extrastriate visual pathway with signals about brightness motion and depth from the parietal visual pathway to compose a representation of an object in space-in this case of an annulus that appears to recede 32

the authors experience during MRI when he observed a continuous succession of receding annuli every 2 seconds in this view the energy of the electroshymagnetic bombardment when released during precessional relaxation flows through the geniculate laminae in the same way that the RTN spindle bursts do that is as a standing wave and thus the visual epiphenomenon is the same in both cases if the subject keeps the eyes focused straight ahead and the attention fixated In a study of phosphenes evoked by electricity in conjunction with hallucinogenic drugs Knoll Kugler Hofer and Lawder found that each subject sees specific kinds of phosphene at different frequencies and that these frequency-specific images are stable enough to be reproduced after six months31

They conclude that the tunability of the electrical stimulation frequenshycies within the EEG range to various definable phosphenes requires the existence of a resonance system One mechanism contributing to that resonance system may be the functional anatomy of the LGN

The colors of receding annuli as functions of geniculate laminar anatomy The colors of receding annuli phosphenes are consistent with the patterns of discharge spindle waves can be expected to stimulate as they move through

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 131

geniculate laminae As shown in Figure 5 the six laminae differ (1) in the types of wavelength signals relayed (2) in physical size and (3) in the area of the VF represented 24-25 Only 4 out of 6 laminae Cparvocellular layers 3shy6) contain TC cells that relay wavelength signals the other 2 laminae (magnocellular layers 1 and 2) do not encode wavelength Among parvocelshylular laminae only lamina 6 the longest and most dorsal layer contains TC cells that can represent the far periphery of the VF (from 800 to 50deg of isoeccenshytdeity) therefore when the spindle wave enters the peripheral VF only those wavelengths relayed by lamina 6 will participate in composing a cortical lightness record (See Zeki)32

I n lamina 6 ganglion cell axons arriving from the retina carry two kinds of wavelength signals (1) center-ON signals from medium-wavelength cones (M-cone center-ON) and long-wavelength cones (L-cone centershy

ON)33-35 Using the cone spectral sensitivity curves (adapted from Marks et al 36) we average the wavelengths that elicit maximal responses for M-cones (535 nanometers) and L-cones (520 nm) which yields a mean wavelength value of 550 nm In humans this wavelength generates a sensation of green or yellowshygreen the sensation observed by the author

As the spindle burst moves ventrodorsally it reaches the dorsal areas in the geniculate laminae which contain TC cells representing the central 0deg to 20deg of isoeccentrieity in the VE All 4 parvocellular laminae have TC cells which are potentially capable of representing this central region of vision but the authors observation that the color of the filling-in disk changed from green to blue implies that in the early years of phosphene induction the spindle wave must have remained close to the surface of the LGN stimulating only laminae 5 and 6 which generates a sensation of yellow-green When the fill-in disk was observed to change color from green to blue the spindle wave must have been rechanneled so that it began to penetrate below laminae 5 and 6 and to activate laminae 3 and 4 the only laminae that relay blue-sensitive signals (Sshycone center-ON signals)3 In light of the authors MRI experience it seems likely that a spindle wave requires a minimum of 2 seconds to reach the blueshysensitive cells of laminae 4 therefore during MRI when the receding annuli disappeared after 2 seconds half the normal duration the fill-disk had a green color even though it had long since change to blue in other induction settings with a 4-second trajectory

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 132

A REPRESENTATION OF THE VISUAL FIELD IN EACH LAMINA

orooqUtftc O-u OCIJ1SALfIOLI (I01flAj

0

10

20

30

40 n50 Of

60

70

20 loO 1Mgr_ II~ o UIpoundAS65 mn1MY-o actlvncL ~~~r

Jll-COMcetlImiddot~

II LAYERSU 3 GatQYancetl~ (1) ucon ceom-oyenF (2)l~cen()FF 3) ~ cenloH

II~ cng1loqctWIIIfNla

iICINe -- (t81Otdb1t1d~OH (2)~

80

B CONE SPECTRAL SENSITIVITY CURVES

S-COHS

WAVIlLllNG1llS OF UGHT IH NANOMllTERS (NM)

Figure 5 Phosphene color as a function of ganglion cell distribution in parvocellular laminae (Aj Schematic drawing ofthe proportion ofthe VF represented in each laminae The proportions shown here are based on the work of Connolly and Van Essen24 The

far periphery of vision (50 0 to 80 0 of isoeccentricity) is represented in only two laminae-laminae 1 and 6-and of these two only lamina 6 is a parvocelLular lamina capable ofencoding wavelength signals Therefore only those wavelengths relayed by lamina 6 will participate in forming a cortical lighmess record for the far periphery of the VP (B) Cone spectral sensitivity curves (adapted from Marks et al)36 Using these cone sensitivity curves we can estimate the sensation stimulated by a spindle wave moving through lamina 6 by averaging the wavelengths that elicit maximal responses for M-cones (535 nanomeshyters) and L-cones (520 nm) which yields a mean wavelength value of550 nm In humans this generates a sensation of green or yellow-green the sensation observed by the author when the receding annulus enters at the far periphery of the VP For a calculation of the cortical lightness record when a spindle wave moves through 20deg to 0deg ofthe VF stimulating all 4 parvocelfular laminae see the text and Figure 6

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 133

Once the spindle wave penetrates to laminae 3 and 4 it may activate all 4 parvocellular laminae stimulating TC cells to send contradictory wavelength signals for the same retinotopic location the signals sent from laminae 4 and 3 will encode blue light (S-cone center-ON plus M-cone center-OFF and Lshycone center-OFF) while the signals sent from laminae 5 and 6 encode yellowshygreen light (M-cone center-ON plus L-cone center-ON) This kind of contrashydiction does not occur in normal retina-based perception where light energy striking the retina is structured by the retinas center-surround and colorshyopponent organization to encode only one set of wavelength signals for each spatial locus 32 In Figure 6 we estimate the cortical lightness record that results when contradictory wavelength signals compete to be represented in consciousshyness Our calculations suggest that the outcome will be a mean wavelength which in humans elicits a dark blue or violet sensation

PART II AMORPHOUS PHOSPHENES amp THALAMIC DELTA ACTMTY

M echanisms controlling the transition from spindle bursts to delta activity In the consensus scenario for the generation of NREMS16-20 we noted that the RTN shifts to firing spindle bursts

when polarization of thalamic cell membranes drops to V m = - 60 mV At the same time cortical cells begin oscillating with a synchronous slow rhythm laquo 1 Hz) Both processes further decrease the Vm of TC cell membranes When Vm = - 75 mY TC cells begin to generate their own intrinsic calcium currents which also decreases V m At V m = - 90 mV RTN neurons stop firing spindle bursts At the same time the TC cells begin firing low-threshold calcium spikes in alternation with after-hyperpolarizations (LTS-AHP) Because sensory relay neurons in the LGN are not linked to one another by locally projecting axons the firing of one TC cell does not excite its neighbor However a lack of local connectivity does not mean that TC cells occupying the same laminae release their AHP-LTS calcium spikes in a random distribshyution rather spikes are released simultaneously by groups of cells in synchrony with the advent of the cortical slow wave In effect the distribution of LTSshyAHP spikes firing in the LGN is determined by the spatial propagation of the cortical slow wave Thus the delta wave (1 to 4 Hz) activity detected by cortical EEG during NREMS is a product of the interaction between the AHP-LTS calcium spikes released by TC cells and the cortical slow rhythm

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 134

CORTICAL PROCESSING OF CONTRADICTORY

WAVELENGTH SIGNALS

KEY _ Cells firing

cJ Cononol firing

Assume that as a spind6e wave moves through the LGNlt fires simultaneously aU the TC cells that represent a particular reUnoshytopic locus (x y) in each of the six laminae As a result cortical cells engaged In the higher level processing of visual signals will receive more wavelength signals representing retina locus (x y) than are generated by normal perception laquo and some of these afferent wavelength signals may contradict other signals arriving simultaneously

CORTICAL LIGHTNESS RECORD SlgnalSell

Intemal contradictions not congruent wilt pre

SmiddotON eristing neuron neta

s bullbull M-ON LmiddotON

3 bullbull M-OFF + L-OFF

a-ON 12

ROD-ON

No Internal eonlradlemiddot

--------1I =~8b~~~~~~~t signals

3+4

~ --OFF Excludes 6 Of 7 $J9n18

1+2 B-ON I

IWmiddotHmiddotI Signal Sell

1111111 No Intern1 conlrfldlcshy lion

Exelvdta 4 out of 7 efshy

bullbullbull bullbullbull ferant signals

No Intern1 contradic_ tionnee S-ON BshyOH and ROO-ON can all be coacllve at low lImlnance levels nef Ihe rod-eone break

ExchJde$ only 2 Ollt of 7 afferent signals

Figure 6 Selection of competing wavelength signals based on neuronal group selection This thought experiment is based on Edelman sconcept ofneuronal group selection 73 We assume that all possible combinations ofsignals will form sets and that all signal-sets will compete to make the most efficient match with pre-existing neuromd networks that have been forged over years ofnorma reti1U1-based perception We also assume that pre-existing neural networks are most likely to expedite those sets that satisfY 2 criteriI (J) the signals in a set do not contradict each other and (2) fower signals are excluded than in the other sets that satisfY the first criterion In our analysis Set 4 wins the competition because it does not contain internal contradictions and excludes fower signals (2 out of 7) than Set 3 excludes (4 out of7) It is not an internal contradiction that Set 4 contains both rods and cone Signtlls in normal retina-based perception when luminance levels approach the rod-cone break S-cone center-ON receptors send signas as do rod receptors and there is even evidence that rod activity may actually drive S-cone activity even after luminance levels foIl below the rod-cone break74 To calculate the cortical lightness record for Set 4 we average the wavelength that elicits maximal responses foom rods (511 nm) and for Sshycones (430 nm) which yields a mean wavelength of 470 nm which in humans results in a dark-blue or violet sensation

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 135

The cortical slow rhythm is an example of a generic pattern of neuronal excitashytion that occurs in large networks of neurons linked by local projections A recent experiment by Maeda Robinson and Kwana38 shows that networks of locally-connected neurons spontaneously generate periodic synchronized bursts of calcium transients that propagate across the network in an expanding spatial wave a pattern that represents a stable mode of firing towards which these neuronal networks relax following perturbations for example by electronic stimulation or by drugs Understanding the characteristics of these waves is an important prerequisite to understanding the mechanisms that produce the amorphous phosphene images as a visual epiphenomenon

To study the spontaneous periodic synchronized bursts the researchers prepared cultures of dissociated cortical neurons and allowed them to mature for several days in vitro (DIV) After 3 to 4 DIV when concenshy

trations of extracellular magnesium were low electrodes began to detect spontaneous synchronized bursts of low frequency calcium transients (between 01 and 1 Hz) that originated in different locations on the sheet every 10 to 20 seconds and spread across the sheet of cells at a relatively slow speed averaging 50 mmsecond The researchers could not predict where a wave would originate or where it would expand rather the initiation and expansion of waves was generated by spatial and temporal summation of a continuous random background of synaptic inputs including miniature spontaneous synaptic events but the pattern was not random since waves propagated sequentially from electrode to electrode as each local group of neurons charges up its neighboring nontefractory areas rather than in a random sequence of regions38

The excitability of the cells in the sheet determines the probability first that there will be a synchronous burst and second that it will spread in a particshyular direction Cells become more excitable as the cultures mature which means the refractory intervals between successive bursts were much shorter in mature cultures (gt 30 DIV) than in early cultures laquo 7 DIV) Some cells became so insensitive to inhibition that they continued to fire bursts even when extracellular concentrations of magnesium were relatively high Finally there were refractory periods of 5 to 10 seconds during which no bursts occurred even when an electrical stimulus was applied This refractory interval for cultured networks is slightly longer than the refractory interval observed of the cortical slow wave in vivo which 25 to 4 seconds 18- 19

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 136

Based on the observations about cortical slow waves we can predict that phosphenes generated as epiphenomena of delta wave activity will present the following signal characteristics (1) signals that appear at unpredictable locations in the VF (2) signals that expand and diverge asymmetrically following unpredictable trajectories which may encompass large areas of the VF (3) signals that move relatively slowly (50 mmsec) (4) signals that recur with a period of 2 to 4 seconds reflecting entrainment by the cortical slow wave (5) signals that do not terminate automatically after a predictable number of cycles

The spatial patterns of phosphene mists and thalamic delta waves are similar The spatiotemporal characteristics of amorphous phosphenes match the pattern of wave propagation associated with periodic spontashy

neous synchronized bursts in large neuron networks the amorphous phosphenes enter the visual field at unpredictable locations expand and diverge asymmetrically with a slow steady rate of flow follow trajectories that are unpredictable and exhibit a refractory interval The amorphous mists do appear to have a periodicity although the author is unable to sustain the vision while also counting the seconds therefore he is unable to determine if it compares to the period of the cortical slow wave (25 to 4 seconds) but his impression is that it feels roughly the same as as with receding annuli which recur at 5 seconds Also the refractory interval feels as if it decreases as the induction session is extended These similarities suggest that the amorphous phosphenes are generated by stage 2 NREMS delta wave activity which is an activity governed by the reverberation of the cortical slow wave in thalamoshycorticothalamic circuits The cortical slow wave is referred to the LGN where it modulates the firing of visual relay cells in the laminae and since relay cells do not have local dendritic connections the expansion of a wave of depolarshyizations moving from one relay cell to the next across in the laminar surface will mirror at least in part the expansion of the cortical wave that is spreading contemporaneously through locally-connected cortical cells

PART III RETENTION OF CONSCIOUSNESS

In a normal transition to NREMS the volley of synchronous spindle bursts that marks the onset of stage 2 NREMS overwhelms the normal firing pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 137

of thalamocortical cells preventing their relay of afferent sensory signals and inducing a loss of consciousness21 But the loss of consciousness cannot be timed precisely using cortical EEG the thalamus is too remote for the onset of spindling to be reliably detected by scalp electrodes39 In experiments with cats where electrodes could be implanted in the thalamus researchers found that spindling often reached peak levels of activity in the thalamus-a level of activity consonant with stage 2 NREMS-at a time when the cortical EEG was still showing intermittent desynchronizations a pattern characteristic of the drowsy stage 1 transition not a fully-established stage 2 NREMS episode4o

In other words there is a short period of time in which the synchronous rhythms of stage 2 NREMS are installed in the thalamus but not in the cortex where cortical neurons continue to depolarize in response to afferent sensory signals

T his finding suggests a possible explanation for the authors ability to retain consciousness while spindle bursts are sweeping through the LGN if he is able to extend the duration of this time lag between

the onset of spindling in the thalamus and spindling in the cortex if he is able to stimulate the visual cortices in such a way that they continue to depolarize then he may be able to keep on processing visual signals-to remain visually aware-even after the non-visual thalamus and non-visual cortex become entrained by synchronous sleep rhythms The authors induction technique includes several behaviors which are known to enhance the responsiveness of visual neurons-eye movements attentive fixation and an attitude of expectancy

Effects of eye movements and attention on the LGN Sustained convergence causes periorbital proprioceptors to send excitatory feedback directly to the LGN41 Also convergence further enhances the excitability of geniculate cells by stimulating the superior collicus (SC) which sends its own excitatory signals to the LGN42-43 These signals from the SC are known to selectively enhance the excitability of visual relay cells that represent the periphery of vision44 We know in the authors case that the SC is being stimulated because he is able to keep on fixating an ability which would normally be lost during the transishytion to NREMS45 The ability to fixate can be retained however if the SC is stimulated (even if stimulated during NREMS)46

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 138

Effects of eye movement attention and expectancy on the primary visual cortex The PET study of mental imagery by Kosslyn et al 3 showed that even a baseline resting state of relaxed immobile expectancy can generate signifishycant increases in neuronal activity in the primary visual cortices Further increases can be induced by sustained eye movements

A sustained convergence will release a stream of ponto-geniculo-occipital (PGO) waves These PGO waves called eye movement potentials or EMPs last only as long as the eye movement1747 whereas the PGO waves associated with rapid-eye-movement sleep (REMS) fire continually for the duration of the REMS episode Both REMS-related PGO waves and EMPs have the same desynchronizing effect on the visual pathways they move through the LGN depolarizing the thalamocortical cells which relay the signals to cortical neurons The responsivity of neurons in the primary visual cortices is enhanced by the stimulation of PGO waves 1747-49 If the passage of EMPs causes the genicushylate relay cells and their cortical targets to depolarize regularly then a volley of 4 spindle bursts moving through the same pathways will register as just another series of depolarizations in effect the spindle bursts are processed by the visual system as if they were sensory signals sent from the retina rather than an event stimulated by endogenous mechanisms

T he impact of eye movements and ftxation on the parietal visual cortex Convergence and attentive fixation will also enhance the responsiveness of light-sensitive parietal visual neurons (PVNs) in area PG of the

posterior parietal cortex 50 In experiments where monkeys are trained to fix their attention on a screen-and to keep on fixating even if no targets appearshythe excitability of these light-sensitive PVNs increases by as much as 350 51

52-53Responsiveness is also facilitated by the angle of gaze Also area PG is the first region in the visual pathways containing individual neurons with the capacity to respond to large bilateral stimuli moving in opposite directions along the central meridians of vision (opponent vector motion) 853-55 Facilitation of PVNs in area PG has the effect of sensitizing the subject to bilateral opponent vector motion and this is especially true if the movement appears in the periphery of the VE 8

Intracortical ampliftcation and feedback to the LGN When PGO waves and signals from the SC arrive in the primary visual cortex they may be relatively weak however weak signals can be amplified by reverberating in large networks

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 139

of cortical cells linked by local projection 56 There are nine times as many excitatory links among cortical cells as there are projections from the visual cortex to the LGN an imbalance which suggests leads Suarez Koch and Douglas to propose that geniculate input provides only a minor fraction of the excitatory input the majority originating in neighboring and recurrently connected cortical cells57 If the excitabiliry of cortical neurons is slightly higher than normal then this process of amplification may continue even after the LGN signals that initiated the reverberation are no longer being transmitted by the LGN ( a hysteretic mode of operation) 57

Feedback from hyperexcited cortical neurons will stream back to the LGN via corticogeniculate projections which outnumber geniculocortical projections ten-to-one One effect of this feedback is that the LGN is

able to absorb large amounts of information flowing back from the cortex 58

As signals reverberate back and forth in thalamocorticothalamic circuits a matching process takes place those geniculate relay cells that fire in patterns consistent with the firing patterns of active cortical cells will have their responshysivity enhanced while those geniculate cells that fire in patterns not consistent with cortical cells will be suppressed 59

Preservation of consciousness by selective facilitation of the visual pathways By combining all of the facilitatory effects produced by the authors eye movements and attentive fixation-(l) stimulation of the LGN by feedback from periorbital proprioception both directly and indirectly via the SC (2) the release of PGO waves (EMPs) that facilitate neurons in the LGN and primary visual cortex as they pass (3) the facilitation of the primary visual cortex by a state of relaxed immobile expectancy (4) attentive fixation and angle of gaze that facilitate PVNs in area PG (5) intracortical amplification of signals received from the LGN and (6) corticogeniculate feedback that stimulates the LGN-we delineate a circuit of enhanced excitability that extends from the LGN through the post-geniculate visual heirarchy to area PG where signals are integrated into representations of objects

The hyperexcitability of neurons all along the post-geniculate visual pathways creates conditions in the visual cortices which are similar to those present during EEG-desynchronized states of waking and REMS Therefore neurons in the visual pathways are too excitable to be entrained by synchronous bursting

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 140

patterns when spindle waves move through them instead the spindle bursts stimulate visual neurons to depolarize and then recover as happens in response to afferent sensory signals during waking states It is important to note that for this to occur none of the constituent neuron assemblies is required to perform an abnormal operation the abnormality is a function of the authors intent to activate contemporaneously neuron assemblies that would not normally be co-activated

PART IV HYPNOTIC ANALGESIA

Manipulation of spatial attention as a method for alleviating pain sensations In a theoretical article on the neurophysiology of hypnosis Crawford and Gruzelier60 propose that variations in hypnotizability are function of variability in the efficiency of the frontolimbic (anterior) attentional system in humans high-hypnotizables are better able to sustain focused attention on a task and to ignore extraneous stimuli than are low-hypnotizables

I na related empirical study that compares the use of attention by subjects with high versus low hypnotizability Crawford Brown and Moon61 report that highly hypnotizable persons continue to show physiological reactivity

while cognitively not perceiving the painful stimuli Through disattentional processes they can dissociate themselves from the awareness of pain The authors phosphene induction behaviors-and the cutaneous analgesia he experishyences-appear to involve the same kind of behaviors that is a mobilization of frontolimbic attention used to withdraw attention from external stimuli and to concentrate it on internally-generated phosphene images This suggests the hypothesis that the mechanisms that generate phosphenes might also produce hypnotic analgesia There are several ways that visual signals and pain signals might interact to produce this analgesia

Competition between pain and vision signals for limbic registration The fully-developed sensation of pain requires integration of rwo kinds of informashytion Signals that encode the location and intensity of a noxious stimulus (nociceptive signals) are relayed via the thalamus to the somatosensory cortices which registers only the sensory-discriminative aspects of pain perception62 before reaching consciousness the nociceptive signals must be sent to the limbic

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 141

system where they are linked with signals from long-term memory that encode the affective significance the stimulus has acquired for that individual Studies of brain metabolism show this linking of somatosensory information with limbic associations takes place in the anterior cingulate (CG) and anterior insula62-64

PET studies also show that the anterior CG is activated when subjects shift their spatial attention in response to expectations as to where

66stimuli will next appear65- This is precisely what takes place during the state of immobile expectancy that induces phosphenes Since visual signals and nociceptive signals both require limbic enhancement which is only possible if they get access to the anterior CG there might be conditions in which the two types of afferent sensory signals have to compete for that access In a theoretical article on the mechanisms of attention Posner and Rothbart67

propose that visual signals can interfere with nociceptive signals by blocking access to the anterior CG As behavioral evidence they cite studies showing that when young infants make distress calls they can be distracted by the presentation of a new visual stimulus We have shown the evidence of such control at about three months Orienting to visual events can be employed to quiet or calm negative vocalizations However the distress appears to be maintained and reappears when the infants attention to the stimulus is reduced Caregivers also report the use or visual orienting to block overt manifestations of distress at about this age 67

The effects of disattention on the somatosensory cortices If there is a competition between visual signals and nociceptive signals for access to the anterior CG it is likely that the competition will be affected by the relative volume of signals received A recent study suggests that focusing attention on internally-generated visual stimuli may reduce the number of nociceptive signals relayed by the somatosensory cortices Drevets Burton Videen Snyder Simpson and Raichle68 have shown that the mere anticipation of a touch at a specific cutaneous site increases the flow of blood to those cortical somatosenshysory neurons that are linked with that site where touch is expected and decreases the flow of blood to neurons linked with sites where touch is not expected In this experiment the researchers designated touch as the behaviorally significant sensory stimulus but their findings suggest that the outcome could be reversed if the instructions were reversed if subjects were

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page J42

instructed to direct attention away from a cutaneous site where a noxious stimulus was being applied if they were instructed to relax close their eyes and concentrate on the play of phosphenes in the visual field as the behaviorally significant sensory stimulus then it would be reasonable to expect that the flow of blood would decrease to the somatosensory neurons linked with the cutaneous stimulus and that the flow of blood would increase to the visual cortices The decrease in blood flow to somatosensory neurons implies less neuronal activity which implies that fewer signals are being sent forward to the anterior CG than would have been sent if instead the subject were treating the touch as the behaviorally significant sensory stimulus If fewer pain signals arrive at the anterior it is reasonable to infer that the conscious experience of pain will be muted by the diversion of attention to internal visual stimuli

Differential impact of sleep rhythms in the visual and nonvisual thalamus There is another mechanism that might also contribute to the analgesic effect of inducing sleep rhythms PET studies show that

the thalamus is involved in the relay of nociceptive signals to the cortex63 although some confusion remains about which kinds of signals are relayed by which subregions in the thalamus62 One thalamic site clearly identified by anatomical studies as a relay for nociceptive signals is the ventroposterior lateral nucleus (VPL)69 If synchronous sleep rhythms are active in the thalamus we can reasonably expect that the VPL will itself be entrained by synchronous oscillations and that it will relay the sleep rhythms to somatosensory cortices Relay neurons in the VPL are not stimulated by feedback from eye movements and fixation as are relay neurons in the LGN which suggests that sleep rhythms may impede the relay of nociceptive signals via the VPL but not the relay of visual signals via the LGN

Brain waves associated with anesthesia and NREMS The hypothesis presented here-that consciousness can be preserved despite the presence of NREMS activity-is consistent with a recent report that the kinds of fast brain waves which are normally associated with conscious states are also present during NREMS and anesthesia two states which were thought to involve minimal brain activityJo Another recent study found that there is a close resemblance between the slow brain waves that appear during NREMS and those that appear during certain types of anesthesia71

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 143

bull bull bull

CONCLUSION

In this paper we have presented evidence supporting the hypothesis that phosphene images can be generated as an epiphenomena of thalamic spindle bursts and delta wave activity normally associated with NREMS The prereqshyuisites for inducing these sleep rhythm phosphenes are relaxed immobile expectancy sustained convergence and attentive fixation of an undifferentiated visual field Our hypothesis provides a necessary and sufficient explanation for the authors induction of phosphenes and perhaps also for the generation of phosphenes reported to appear spontaneously during the drowsy transition to sleep (hypnagogic states) during sensory deprivation or during certain kinds of prayer or meditation all of which involve a similar state of relaxed immobile expectancyJ2

CORRESPONDENCE Philip T Nicholson bull 52 Norfolk Road bull Chestnut Hill MA 02167

REFERENCES amp NOTES

1 M 1 Posner Modulation by Instruction Nature 373 (1995) pp 198-199 2 J Reissenweber E David amp M pfotenhauer Investigations of Psychological Aspects of

the Perception of Magnetophosphenes and Electrophosphenes Biomedizinische Tecknik 373 (1992) pp 42-45

3 S M Kosslyn W L Thompson 1 J Kim amp N M Alpert Topographical Representations of Mental Images in Primary Visual Cortex Nature 378 (I995) pp 496-498

4 P E Roland amp B Gulyas Visual Memory Visual Imagery and Visual Recognition of Large Field Patterns by the Human Brain Functional Anatomy by Positron Emission Tomography Cerebral Cortex 51 (1995) pp 79-93

5 H Benson The Relaxation Response (Morrow New York NY 1975) 6 ] H Schultz amp W Luthe Autogenic Training a Physiological Approach to Psychotherapy

(Grune amp Stratton New York NY 1969) 7 E Jacobson Progressive Relaxation (University of Chicago Press Chicago IL 1938) 8 M A Steinmetz BC Motter C] DuffY amp V B Mountcastle Functional Properties

of Parietal Visual Neurons Radial Organization of Directionalities Within the Visual Field Journal ofNeuroscience 71 (1987) pp 177-191

9 R R Edelman Magnetic Resonance Imaging of the Nervous System Discussions in Neuroscience 71 Elsevier Science Amsterdam (I990) also J H Newhouse amp ] I Wiener Understanding MRI 1st Ed (Little Brown Boston MA 1991)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 144

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

bation takes place at the center of the cloud the phosphene ebbs away from this region leaving a tiny dark hole then the phosphene fills back in then it ebbs and fills again-a fluctuation that continues as long as the phosphene cloud is visible During the perturbations the phosphene vaguely resembles the iris of a human eye with an interior dark space as its pupil This eyeshyimage is seldom symmetrical and its boundaries are always changing

(c) TWO-TONE PHOSPHENE When the phosphenes are induced over a prolonged period of time the phosphene in the central region representing foveal vision presents a more intensely bright more opaque (finely-grained) character than the rest of the cloud as shown in Figure 2(C) When this brilliant opaque phosphene appears as part of an eye-image it forms a thin rim surrounding the pupiL From this rim flares jut out into the dark pupil space coil about merge or recede back into the rim

The periodic unidirectional amorphous waves do not terminate after a stereoshytyped sequence they can be evoked over prolonged rime periods if the autohypshynotic behaviors are maintained The author is unable to retain the vision of these amorphous waves while simultaneously counting the number of seconds elapsed it is his impression however that the duration of amorphous expanding waves feels about the same as for receding annuli that is a duration of about 4 seconds per wave The amorphous waves usually appear in clusters followed by a refractory interval during which no phosphenes appear even if induction behaviors are sustained

PHOSPHENES SUPERIMPOSED ON ExTERNAL OBJECTS

The author can observe amorphous phosphene images with his eyes open if he is in a room dark enough that colors cannot be distinguished or if he is

in a lighted room but one where he can keep his eyes diffusely focused on a relatively undifferentiated surface such as a wall or ceiling with a light and uniform color and no distracting decorative adornments In open-eye viewings phosphenes appear as faint translucent waves of yellow-green mist

superimposed over the surface or in the dark space that fills the darkened room If the author attempts to focus on the features of external objects the phosphenes disappear

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 120

RECEDING ANNuLI EVOKED BY MAGNETIC REsONANCE IMAGING (MRI)

A s a patient undergoing an MRI scan the author observed an unusual sequence of receding annuli He was not relaxed as in a normal induction but rather anxious about his medical condition and about

being confined in the narrow MRI tube To keep calm he concentrated on breathing slowly and stared straight ahead While the sound of MRI machine was audible the author observed a stream of receding annuli that differed from the usual sequence (self-induced and hypnagogic) in three ways (I) the MRI annuli did not terminate at 4 cycles but continued for as long as the author kept his attention focused (2) the MRI annuli were only yellowshygreen in color even though in other inductions the fill-in disk had already changed from green to blue and (3) MRI annuli completed their trajectoshyries in half the normal time disappearing in 2 seconds instead of 4 An interval of 2 seconds between radio pulses is often selected as optimal interval for capture of the signals emitted by hyperexcited atoms in the subjects body

10during the precessional relaxation 9- These observations suggest that energy released in the wake of the radio bombardment during MRI moves through the LGN as a standing wave in the same way that spindle bursts move but that the 2-second duration of the MRI wave is not long enough to activate the neurons that generate a blue sensation

THE ANESTHETIC EFFECT ASSOCIATED WITH SELF-INDUCED

PHOSPHENES

On several occasions the author has preferred to undergo minor surgery without local anesthetic and to rely instead on autohypnotic analgesia-for example during extraction of an infected abscess from the back during laser surgery to

remove keloids and during the filllng of dental caries His experience on a recent occasion when a dentist had to abrade the surface of six teeth with damaged enamel in order to create a strong bonding surface are worth describing here because the experience implies that spindle waves can be induced even during a state of high physiological arousal For this appointshyment the author arrived in the office too late to hypnotize himself in advance

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 121

so he had to begin the normal induction procedures after the dental work was already underway

A s the dentist worked on the first tooth the author experienced apprehension sharp sensations of pain and an involuntary tensing of the large muscles of the body with each application of the drill As

the author kept his eyes converged and his attention focused on the center of the visual field the involuntary tensing in response to pain alternated with a precipitous relaxing of those same muscles immediately after the stimulus With the repeated relaxation came a sense of relief and of letting go that amelioshyrated the pain The pain-driven relaxation was much stronger than the relaxation that normally accompanies the authors self-induction of phosphenes and the alternation of a pain-driven tensing on one hand and the distancing effect of focusing attention on the visual field on the other hand resulted in a rapid dissociation from all external and internal stimuli including a signifishycant amelioration of painful sensations

Most striking is the fact that by the time the dentist reached the third toothshyafter only a few minutes of this pain-driven self-hypnosis-the author saw a normal sequence of 4 receding annuli followed by swirling clouds of amorphous expanding phosphene even though the dentist was still using the drill contemporaneously This experience suggests that thalamic sleep rhythms can be voluntarily induced even when the subjects level of physiological arousal is high

SIMILARITIES WITH ATTENTION-INDUCED PHOSPHENES

REpORTED BY OTHER OBSERVERS

Taxonomies of phosphene images always include examples of simple geometric phosphenes with circular or semi-circular shapes (disks annuli or crescents) as

14well as formless phosphene mists 11 - There are also a number of anecdotal accounts that are relevant for example Friedman an opthamologist who studied entoptic images by introspection describes a similar sequence of annuli induced by sustained inward concentration Circular waves of blue color may be seen in the dark by the dark adapted retina They start at the

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 122

periphery and move inward toward the macula as a concentrically contracting solid circle disappear at the macula and begin again at the peripheryl)

A valuable but often-neglected resource of information about phosphene imagery is presented in the literature of religious mysticism Many mystics reported having seen translucent colored lights while absorbed in prayer or meditation A list of descriptions excerpted from self-reports is presented in Table 1 (These excerpts are representative of phosphene images that appear during states of calm and inward-oriented concentration they do not include images associated with paroxysmal raptures) These phosphene images exhibit a relatively limited set of shapes and colors the shapes are either circular (eg rings disks wheels suns) or formless (eg mists snow smoke) and the colors are usually a variant of either green or blue The phosphene visions of mystics display shapes and colors that are comparable to the images described by the author this and the many similarities in the behaviors used to induce phosphenes suggest that both sets of phosphenes have a common etiology

DISCUSSION

Whether the author uses self-hypnosis to induce phosphenes or experishyences them as hypnagogic images the threshold sequence of receding annuli has the same characteristics In both these

instances the antecedent behaviors involve a state of low physiological arousal combined with mental withdrawal from external stimuli These parallels suggest the hypothesis that phosphene displays are related to sleep-wake transitions

PART I RECEDING ANNULI AND THALAMIC SPINDLES

Mechanisms controlling the transition from waking to NREMS Based on the work of several research teams16-20 a consensus scenario for the generation of NREMS has emerged In this scenario NREMS is the product of three brain rhythms that interact with each other in thalamocorticothalamic circuits During the drowsy transition to sleep which in humans is called stage l NREMS the low voltage activity in the cortical electroencephalograph (EEG) still shows a pattern of intermittent desynchronization The polarization of

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 123

Table I Excerpts from self-reports of light visions by religious mystics

HEBREW MYSTICS the appearance of the wheels was like the gleaming of beryl and the four had the same form

their construction being something like a wheel within a wheel Ezekiel like a dome shining like crystal spread out about their heads And above the dome something

like a rhrone in appearance like sapphire Ezekiel a round Iodder like a full sphere rolling back and forth before him bright blue R Abulafia A glowing light clear brilliance A purple light that absorbs all lights R Moses de Leon

HINDU AND BUDDHIST MYSTICS a perfectly round beautiful deep-blue shape of a size appropriate to the center of a mandala as

if exquisitely painted of extreme c14rity Tsong Khapa a luminous revolving disc studded with lights a lotus flower in full bloom Gopi Krishna both my eyes became cemered When this happened a blue light arose in my eyes like

a candle flame without a wick and stood motionless in the ajna chakra S Muktananda

MUSLIM MYSTICS [like] chandelierssublime lights [like] stars moon or the sun Sharafuddin aI-Maneri its color is deep blue it seems to be an upsurge like water foom a spring Najmoddin Kobra visualize yourself as lying at the bottom of a well [looking up at the light of the opening] and

the well in lively downward movement Najmoddin Kobra the color green is the suprasensory uniting all the suprasensories Alaoddawleh Semnani the light rises in the Sky of the hean taking the form of light-gilling moons Najm Razi

CHRISTIAN MYSTICS his own state at prayer resembles a sapphire it is as clear and bright as the sky Evagrius descending like a bright cloud of mist like a sun round as a circle Simeon Neotheologos saw something in the air near him He did not understand the rype of thing but in some ways

it appeared to have the form of a serpent with many things that shone like eyes although they were not eyes Ignatius of Loyola

the soul puts on a green amilia [cape worn on shoulders beneath armor] John of the Cross [the almilla is like a helmet which] coverS all the senses of the head of the soul It has one

hole rhrough which the eyes may look upwards John of the Cross a round thing about rhe size of a rixdaier all bright and clear with light like a crystal H Hayen I saw a bright light and in this light the figure of a man the color of sapphireblazing with a

gentle glowing fire the three were in one light Hildegard von Bingen saw a b14zing fire incomprehensible inextinguishable with a flame in it the color of the sky

Hildegard von Bingen saw placed beneath her fuet the whole machine of the world as if it were a wheel She saw herself phced

above it her eyes of contemplation magnetized towards the incomprehensible Beatrice of Nazareth I saw the eyes I do not know if I was asleep or awake Angela of Foligno kind of sunlit winged being like a childs head beneath two little wings Abbess Thaisia laquobullbull round patterns small circles would expand and eventually dissipate only to be followed by other small

circles of light Philip St Romain an extraordinary circle of gold light pulsating against a deep violet background There were

always four or fille As soon as one would fode another would appear Philip St Romain

middotItalics added to mark words referring to (l) rings appearing in sets of four (2) amorphous shapes such as clouds or flames (3) circular or eye-like shapes (4) colors from the center of the visible spectrum (gold yellow yellow-green green bluish green) and (5) colors from the lower end of rhe visible spectrum (blue purple violet)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 124

cell membranes (Vm) has already begun to drop (hyperpolarize) in the thalamic reticular nucleus (RTN) a thin sheath of GABAnergic inhibitory neurons that acts as a pacemaker When the Vm of RTN cell membranes drops to approximately V m -60 millivolts (mV) RTN cells stop firing single spikes which are associated with waking states and instead begin firing highshyamplitude 7-14 Hertz (Hz) spike-bursts These bursts wax and wane over 1 to 3 seconds-hence the name spindle -and recur at 3 to 10 seconds Spindle volleys are relayed across the cortical mantle by thalamocortical (TC) sensory relay cells In human studies the primary criterion for onset of the first fullyshyestablished episode of NREMS or stage 2 sleep is the presence of globalized spindles in the cortical EEG

When spindle bursts from the RTN stimulate TC cells to fire in synchrony this synchronous bursting pattern overwhelms the normal capacity of TC cells to relay afferent sensory signals The loss of consciousness at the onset of stage 2 NREMS is thought to be caused by this blocking effect 21

While the RTN is firing spindle bursts through the thalamus another process is activated in the cortex large numbers of cells across the cortical mantle begin to oscillate at a very low frequency laquo 1 Hz)

The cortical slow rhythm referred back to the thalamus via corticothalamic circuits intensifies the hyperpolarizing effect of the RTN spindle bursts on TC cell membranes When V m -75 mV the TC cells begin to generate their own intrinsic calcium currents which further increases hyperpolarization At V m -90 mV the RTN neurons stop firing spindle bursts The TC cells continue to fire low-threshold calcium spikes in patterns which are controlled by the cortical slow rhythm The interaction of these two oscillations generates the delta waves (1 to 4 Hz) which are associated with stage 2 NREMS

In a study of sleep rhythms using the cortical EEG Uchida Atsumi and Kojima found that the mean number of spindles required to induce delta wave activity (that is to induce Vm = -90 mY) is 478 plusmn 162 spindles (from 3 to 7 spindles)22 The mean number of spindles in a volley remains the same for a single individual over multiple trials

Based on the consensus scenario for generation of NREMS we can predict that a phosphene image generated as an epiphenomenon of a thalamic spindle

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 125

Table II Dara show rhe degree of correspondance berween rhe pulse panerns of rhalamic spindles based on intracellular research and rhe sparioremporal panerns of receding annuli phosphenes induced by rhe author using a rechnique of self-hypnosis

Receding annuli phosphenes Thalamic spindle bursrs

Mean number of signals 4 annuli 487 (plusmn 16) bursrs

Sparial exrension vs Thin band 1 - 3 seconds durarion of signal ( 05 -15 cm)

Periodicity of signals 5 seconds 3 - 10 seconds

Simultaneity in LGNs Yes Yes

Point of entry Peripheral VF Ventral amp lareral LGN

Trajecrory Bilareral concentric Unknown

Rare of flow Cons rant rare Unknown

Signal-ro-noise rario High High (shorr bursrs) (sharp brighr discrere)

Termination of sequence Mrer 4 signals Mrer 487 (plusmn 16) signals

will present the following characteristics (1) a high-definition burst-like signal (2) that recurs within 3 to 10 seconds (3) that follows a trajectory compatible with having entered the LGN from the RTN (4) that has a predictable mean for the individual subject and a range that falls somewhere between 2 to 7 annuli and (5) that the spindles will terminate automatically

The temporal patterns of receding annuli and thalamic spindle bursts are similar Table II illustrates the close match between the timing of receding annuli phosphenes and thalamic spindle bursts The most striking similarities are the mean number of signals required to induce termination (4 annuli versus 487 spindles) and the interval between signals (5 seconds for annuli versus 3shyto-lO seconds for spindle bursts) Neither alpha theta nor beta waves present this kind of stereotyped temporal pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 126

T he spatial features of receding annuli are functions of geniculate anatomy A spindle burst moving through the LGN to the cortex will acquire certain distinctive spatiotemporal characteristics because of the

unique curvilinear and laminar anatomy of the LGN A drawing of a macaque LGN based on a clay model constructed by Le Gros Clark23 is shown in Figure 3 The primate LGN is composed of six sheets of cells or laminae that fold over a central hylus In macaques the hylus rises steeply as it extends rostrocausally forming a high arch at the posterior pole in humans the hylus is much more shallow but the functional anatomy is thought to be essentially

23 24the same in both cases - The geometry of the arch forces each lamina to bend so as to constitute in effect one-half of a conical surface and each lamina with its hemi-conical shape contains visual relay cells representing the contralatshyeral half of the visual field (VF) Operating as a pair the complementary hemishycones of the right and left LGN form the functional equivalent of a single conical surface which represents the entire VE This conical geometry of the paired LGNs means a burst of otherwise formless excitation will acquire a distinctive shape as it propagates through the laminae of the LGN Imagine a horizontal section moving along the surface of a cone from base to apex that moving section forms an annulus that shrinks in diameter as it approaches the apex but retains its annular symmetry throughout its trajectory

Figure 3 also includes drawings that show how Connolly and Van Essen24

converted the 3-dimensional structure of lamina 6 the largest and most dorsal layer into a 2-dimensional map Connolly and Van Essen used data obtained by Malpelli and Baker25 to superimpose a grid that specifies the areas in lamina 6 that contain TC cells representing various degrees of isoeccentricity in the VE We will use this map at a later point to show how the movement of a spindle wave through a pair of LGNs correlates with what appears in the VE

The location of the RTN relative to the LGN is also shown in Figure 3 The RTN spindle pacemaker is a thin sheath of GABAnergic inhibitory cells that extends along the surface of the whole posterior ventral thalamus not just the LGN This extension brings the RTN into close proximity with the portion of the LGN (lateral wing) that protrudes out from the main body of the thalamus Some of RTN wraps around and beneath the ventral edges of the LGN26 The RTN comes closest to the LGN in two areas along the ventral edges of the longest laminae (lamina 6 and 1) and along the edge of the lateral

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 127

DORSAL POLE DORSALPOIEA B

L1 L4 L3 L

DORSAL POlE DORSAL POIE (FOVEA)

G LATERAL WING

25

DORSAL POL (FOVEA)

10 _DIAL

20 WING

~

wing These areas contain TC cells that represent the far periphery of the VE If a spindle burst enters the LGN at locations where laminae are in closest proximity to the RTN-along the ventral edges-then the discharge of TC cells will begin in the most ventral portions of the laminae the regions that represent the far periphery of the VE This matches the phosphene sequence observed by the author

Our hypothesis about how this proximity between RTN and LGN affects the trajectory of spindle waves is illustrated in Figure 4 We propose that it is not possible for the author to observe a thin annulus of phosphene sweeping in from all 3600 of the peripheral VF unless spindle bursts exhibit the following

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 128

Figure 3 [facing page Drawings of primate geniculate anatomy and functional anatomy relevant to the generation ofphosphenes (A) Anterior view ofa macaque monkey LGN based on a clay model reconstruction by Le Gros Clark 23 (B) Posterior view ofthe same model showing 6 laminae folded over a central hylus to form lateral and medial wings with the hylus arching steeply upward near the posterior pole to shape the laminae into layers of hollow half-cones nested together Note that the lateral wing of the LGN is slightly larger than the medial wing so that in situ the lateral wing protrudes out from the main body of the thalamus creating a small knob visible during dissection 26 (C) Schematic drawing of an oblique section through median axis (also adapted from Le Gros Clark13 showing how the laminae fuse together at the anterior pole The afferent ganglion cell axons that form the optic tract (OT) penetrate through the anterior surface to reach their target relay cells in the laminae (D) Drawing of the most dorsal lamina-layer 6--separated from the rest of the LGN The geometric shape is a hollow half-cone so that right and left LGNs placed back-to-back form in effect a single cone Note also the position ofthe RTN shown here as a striped bar relative to lamina 6 The position of the striped bar shows that the RTN makes direct contact with lamina 6 at the edge ofthe lateral wing and also along the ventral edges (E - F) Schematic drawings adapted from Connolly and Van Essen24 that show how a 3-dimensional lamina-lamina 6--can be transformed into a 2-dimensional triangular figure lamina 6 is removed and its wings unfolded (E) creating a slightly asymmetric triangular figure (F) which is adjusted to an oblong shape (G) in order to superimshypose a grid matrix with minimal distortion The grid plots locations of TC cells that represent various isoelevations and isoazimuths in the VF locations derived from the experimental observations published by Malpeli and Baker 25 Note the relatively large amounts of laminar surface allocated to central vision (0 0

- 30 0) as compared

to peripheral vision (30 0 - 80 0)

characteristics (1) Spindle bursts must move simultaneously through both geniculate nuclei This pattern of movement is consistent with anatomical studies in primates that found axonal projections linking the right and left RTNs27-28 and with experimental studies in cats that found spindles appearing simultaneously in both right and left thalami 29 (2) Spindle waves must enter the ventral edges of the LGN first and move ventrodorsally in a highly coherent pattern-moving in effect as a standing wave This pattern of movement is consistent with in vitro experiments using sagittal slices from a ferret LGN where spindle waves originated spontaneously at the edge of a slice in an area which contains cells that represent peripheral vision then propagated toward that area of the slice containing cells that represent central vision in the ferret 3o

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 129

VF

PG BIlateral receptive lleJd of PVN YI(j Inward dmKooflality Adapled

0-- from Mortgr at at (1987)

V1

ibull t bull

RTN t t t t t t 1middot3 SECOlO BURSTS OF 7middot14 HZ SPiKES RECURRNG EVERY 3 10 SECONDS

To our knowledge the LGN is the only anatomical structure in the visual system that has the capacity of passively forcing a wave of excitation to flow across a conical surface thereby generating the sensation of a phosphene annulus that retains its symmetry as it shrinks in diameter The retina has a circular anatomy but it is not likely that the mechanical deformation of the retina would produce a wave that began simultaneously in all 3600 of the retinal rim nor that the symmetry of annular wave would be preserved as it flows inward toward the foveal region

The hypothesis presented here-that there is a structure in the visual system that imprints a conical shape on standing waves that move through it-explains

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 130

Figure 4 facing page Schematic drawing of contemporaneous events in selected regions of the visual processing hierarchy (A) The left and right RTNs fire spindle bursts simultaneously (B) The bursts pass through the right and left geniculate laminae as standing waves of depolarization entering from the ventral edges and moving ventrodorsally in parallel In order for the phosphene annulus to appear to be flowing at a constant rate the spindle wave flowing through the LCN must expand in width as it ascends ventrodorsally so that by the time the fill-in disk appears-when the center 30deg of the VF is covered by the phosphene annulus-the spindle wave must have expanded enough to activate relay cells in the most dorsal 50 of lamina 6 (C) Signals representing two complementary hemi-annuli are kept separate in the primary visual cortices (area VI) (D) Signals representing the two hemi-annuli are integrated into signals of a single annulus when they reach area PC in the posterior parietal cortex where the receptive fields of single parietal visual neurons have the capacity to register bilateral signals that exhibit opponent vector movement (that is signals converging from opposite directions along the central axes-as if an object were moving away from the viewer)46 Neurons in area PC also integrate wavelength (color) signals from the extrastriate visual pathway with signals about brightness motion and depth from the parietal visual pathway to compose a representation of an object in space-in this case of an annulus that appears to recede 32

the authors experience during MRI when he observed a continuous succession of receding annuli every 2 seconds in this view the energy of the electroshymagnetic bombardment when released during precessional relaxation flows through the geniculate laminae in the same way that the RTN spindle bursts do that is as a standing wave and thus the visual epiphenomenon is the same in both cases if the subject keeps the eyes focused straight ahead and the attention fixated In a study of phosphenes evoked by electricity in conjunction with hallucinogenic drugs Knoll Kugler Hofer and Lawder found that each subject sees specific kinds of phosphene at different frequencies and that these frequency-specific images are stable enough to be reproduced after six months31

They conclude that the tunability of the electrical stimulation frequenshycies within the EEG range to various definable phosphenes requires the existence of a resonance system One mechanism contributing to that resonance system may be the functional anatomy of the LGN

The colors of receding annuli as functions of geniculate laminar anatomy The colors of receding annuli phosphenes are consistent with the patterns of discharge spindle waves can be expected to stimulate as they move through

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 131

geniculate laminae As shown in Figure 5 the six laminae differ (1) in the types of wavelength signals relayed (2) in physical size and (3) in the area of the VF represented 24-25 Only 4 out of 6 laminae Cparvocellular layers 3shy6) contain TC cells that relay wavelength signals the other 2 laminae (magnocellular layers 1 and 2) do not encode wavelength Among parvocelshylular laminae only lamina 6 the longest and most dorsal layer contains TC cells that can represent the far periphery of the VF (from 800 to 50deg of isoeccenshytdeity) therefore when the spindle wave enters the peripheral VF only those wavelengths relayed by lamina 6 will participate in composing a cortical lightness record (See Zeki)32

I n lamina 6 ganglion cell axons arriving from the retina carry two kinds of wavelength signals (1) center-ON signals from medium-wavelength cones (M-cone center-ON) and long-wavelength cones (L-cone centershy

ON)33-35 Using the cone spectral sensitivity curves (adapted from Marks et al 36) we average the wavelengths that elicit maximal responses for M-cones (535 nanometers) and L-cones (520 nm) which yields a mean wavelength value of 550 nm In humans this wavelength generates a sensation of green or yellowshygreen the sensation observed by the author

As the spindle burst moves ventrodorsally it reaches the dorsal areas in the geniculate laminae which contain TC cells representing the central 0deg to 20deg of isoeccentrieity in the VE All 4 parvocellular laminae have TC cells which are potentially capable of representing this central region of vision but the authors observation that the color of the filling-in disk changed from green to blue implies that in the early years of phosphene induction the spindle wave must have remained close to the surface of the LGN stimulating only laminae 5 and 6 which generates a sensation of yellow-green When the fill-in disk was observed to change color from green to blue the spindle wave must have been rechanneled so that it began to penetrate below laminae 5 and 6 and to activate laminae 3 and 4 the only laminae that relay blue-sensitive signals (Sshycone center-ON signals)3 In light of the authors MRI experience it seems likely that a spindle wave requires a minimum of 2 seconds to reach the blueshysensitive cells of laminae 4 therefore during MRI when the receding annuli disappeared after 2 seconds half the normal duration the fill-disk had a green color even though it had long since change to blue in other induction settings with a 4-second trajectory

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 132

A REPRESENTATION OF THE VISUAL FIELD IN EACH LAMINA

orooqUtftc O-u OCIJ1SALfIOLI (I01flAj

0

10

20

30

40 n50 Of

60

70

20 loO 1Mgr_ II~ o UIpoundAS65 mn1MY-o actlvncL ~~~r

Jll-COMcetlImiddot~

II LAYERSU 3 GatQYancetl~ (1) ucon ceom-oyenF (2)l~cen()FF 3) ~ cenloH

II~ cng1loqctWIIIfNla

iICINe -- (t81Otdb1t1d~OH (2)~

80

B CONE SPECTRAL SENSITIVITY CURVES

S-COHS

WAVIlLllNG1llS OF UGHT IH NANOMllTERS (NM)

Figure 5 Phosphene color as a function of ganglion cell distribution in parvocellular laminae (Aj Schematic drawing ofthe proportion ofthe VF represented in each laminae The proportions shown here are based on the work of Connolly and Van Essen24 The

far periphery of vision (50 0 to 80 0 of isoeccentricity) is represented in only two laminae-laminae 1 and 6-and of these two only lamina 6 is a parvocelLular lamina capable ofencoding wavelength signals Therefore only those wavelengths relayed by lamina 6 will participate in forming a cortical lighmess record for the far periphery of the VP (B) Cone spectral sensitivity curves (adapted from Marks et al)36 Using these cone sensitivity curves we can estimate the sensation stimulated by a spindle wave moving through lamina 6 by averaging the wavelengths that elicit maximal responses for M-cones (535 nanomeshyters) and L-cones (520 nm) which yields a mean wavelength value of550 nm In humans this generates a sensation of green or yellow-green the sensation observed by the author when the receding annulus enters at the far periphery of the VP For a calculation of the cortical lightness record when a spindle wave moves through 20deg to 0deg ofthe VF stimulating all 4 parvocelfular laminae see the text and Figure 6

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 133

Once the spindle wave penetrates to laminae 3 and 4 it may activate all 4 parvocellular laminae stimulating TC cells to send contradictory wavelength signals for the same retinotopic location the signals sent from laminae 4 and 3 will encode blue light (S-cone center-ON plus M-cone center-OFF and Lshycone center-OFF) while the signals sent from laminae 5 and 6 encode yellowshygreen light (M-cone center-ON plus L-cone center-ON) This kind of contrashydiction does not occur in normal retina-based perception where light energy striking the retina is structured by the retinas center-surround and colorshyopponent organization to encode only one set of wavelength signals for each spatial locus 32 In Figure 6 we estimate the cortical lightness record that results when contradictory wavelength signals compete to be represented in consciousshyness Our calculations suggest that the outcome will be a mean wavelength which in humans elicits a dark blue or violet sensation

PART II AMORPHOUS PHOSPHENES amp THALAMIC DELTA ACTMTY

M echanisms controlling the transition from spindle bursts to delta activity In the consensus scenario for the generation of NREMS16-20 we noted that the RTN shifts to firing spindle bursts

when polarization of thalamic cell membranes drops to V m = - 60 mV At the same time cortical cells begin oscillating with a synchronous slow rhythm laquo 1 Hz) Both processes further decrease the Vm of TC cell membranes When Vm = - 75 mY TC cells begin to generate their own intrinsic calcium currents which also decreases V m At V m = - 90 mV RTN neurons stop firing spindle bursts At the same time the TC cells begin firing low-threshold calcium spikes in alternation with after-hyperpolarizations (LTS-AHP) Because sensory relay neurons in the LGN are not linked to one another by locally projecting axons the firing of one TC cell does not excite its neighbor However a lack of local connectivity does not mean that TC cells occupying the same laminae release their AHP-LTS calcium spikes in a random distribshyution rather spikes are released simultaneously by groups of cells in synchrony with the advent of the cortical slow wave In effect the distribution of LTSshyAHP spikes firing in the LGN is determined by the spatial propagation of the cortical slow wave Thus the delta wave (1 to 4 Hz) activity detected by cortical EEG during NREMS is a product of the interaction between the AHP-LTS calcium spikes released by TC cells and the cortical slow rhythm

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 134

CORTICAL PROCESSING OF CONTRADICTORY

WAVELENGTH SIGNALS

KEY _ Cells firing

cJ Cononol firing

Assume that as a spind6e wave moves through the LGNlt fires simultaneously aU the TC cells that represent a particular reUnoshytopic locus (x y) in each of the six laminae As a result cortical cells engaged In the higher level processing of visual signals will receive more wavelength signals representing retina locus (x y) than are generated by normal perception laquo and some of these afferent wavelength signals may contradict other signals arriving simultaneously

CORTICAL LIGHTNESS RECORD SlgnalSell

Intemal contradictions not congruent wilt pre

SmiddotON eristing neuron neta

s bullbull M-ON LmiddotON

3 bullbull M-OFF + L-OFF

a-ON 12

ROD-ON

No Internal eonlradlemiddot

--------1I =~8b~~~~~~~t signals

3+4

~ --OFF Excludes 6 Of 7 $J9n18

1+2 B-ON I

IWmiddotHmiddotI Signal Sell

1111111 No Intern1 conlrfldlcshy lion

Exelvdta 4 out of 7 efshy

bullbullbull bullbullbull ferant signals

No Intern1 contradic_ tionnee S-ON BshyOH and ROO-ON can all be coacllve at low lImlnance levels nef Ihe rod-eone break

ExchJde$ only 2 Ollt of 7 afferent signals

Figure 6 Selection of competing wavelength signals based on neuronal group selection This thought experiment is based on Edelman sconcept ofneuronal group selection 73 We assume that all possible combinations ofsignals will form sets and that all signal-sets will compete to make the most efficient match with pre-existing neuromd networks that have been forged over years ofnorma reti1U1-based perception We also assume that pre-existing neural networks are most likely to expedite those sets that satisfY 2 criteriI (J) the signals in a set do not contradict each other and (2) fower signals are excluded than in the other sets that satisfY the first criterion In our analysis Set 4 wins the competition because it does not contain internal contradictions and excludes fower signals (2 out of 7) than Set 3 excludes (4 out of7) It is not an internal contradiction that Set 4 contains both rods and cone Signtlls in normal retina-based perception when luminance levels approach the rod-cone break S-cone center-ON receptors send signas as do rod receptors and there is even evidence that rod activity may actually drive S-cone activity even after luminance levels foIl below the rod-cone break74 To calculate the cortical lightness record for Set 4 we average the wavelength that elicits maximal responses foom rods (511 nm) and for Sshycones (430 nm) which yields a mean wavelength of 470 nm which in humans results in a dark-blue or violet sensation

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 135

The cortical slow rhythm is an example of a generic pattern of neuronal excitashytion that occurs in large networks of neurons linked by local projections A recent experiment by Maeda Robinson and Kwana38 shows that networks of locally-connected neurons spontaneously generate periodic synchronized bursts of calcium transients that propagate across the network in an expanding spatial wave a pattern that represents a stable mode of firing towards which these neuronal networks relax following perturbations for example by electronic stimulation or by drugs Understanding the characteristics of these waves is an important prerequisite to understanding the mechanisms that produce the amorphous phosphene images as a visual epiphenomenon

To study the spontaneous periodic synchronized bursts the researchers prepared cultures of dissociated cortical neurons and allowed them to mature for several days in vitro (DIV) After 3 to 4 DIV when concenshy

trations of extracellular magnesium were low electrodes began to detect spontaneous synchronized bursts of low frequency calcium transients (between 01 and 1 Hz) that originated in different locations on the sheet every 10 to 20 seconds and spread across the sheet of cells at a relatively slow speed averaging 50 mmsecond The researchers could not predict where a wave would originate or where it would expand rather the initiation and expansion of waves was generated by spatial and temporal summation of a continuous random background of synaptic inputs including miniature spontaneous synaptic events but the pattern was not random since waves propagated sequentially from electrode to electrode as each local group of neurons charges up its neighboring nontefractory areas rather than in a random sequence of regions38

The excitability of the cells in the sheet determines the probability first that there will be a synchronous burst and second that it will spread in a particshyular direction Cells become more excitable as the cultures mature which means the refractory intervals between successive bursts were much shorter in mature cultures (gt 30 DIV) than in early cultures laquo 7 DIV) Some cells became so insensitive to inhibition that they continued to fire bursts even when extracellular concentrations of magnesium were relatively high Finally there were refractory periods of 5 to 10 seconds during which no bursts occurred even when an electrical stimulus was applied This refractory interval for cultured networks is slightly longer than the refractory interval observed of the cortical slow wave in vivo which 25 to 4 seconds 18- 19

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 136

Based on the observations about cortical slow waves we can predict that phosphenes generated as epiphenomena of delta wave activity will present the following signal characteristics (1) signals that appear at unpredictable locations in the VF (2) signals that expand and diverge asymmetrically following unpredictable trajectories which may encompass large areas of the VF (3) signals that move relatively slowly (50 mmsec) (4) signals that recur with a period of 2 to 4 seconds reflecting entrainment by the cortical slow wave (5) signals that do not terminate automatically after a predictable number of cycles

The spatial patterns of phosphene mists and thalamic delta waves are similar The spatiotemporal characteristics of amorphous phosphenes match the pattern of wave propagation associated with periodic spontashy

neous synchronized bursts in large neuron networks the amorphous phosphenes enter the visual field at unpredictable locations expand and diverge asymmetrically with a slow steady rate of flow follow trajectories that are unpredictable and exhibit a refractory interval The amorphous mists do appear to have a periodicity although the author is unable to sustain the vision while also counting the seconds therefore he is unable to determine if it compares to the period of the cortical slow wave (25 to 4 seconds) but his impression is that it feels roughly the same as as with receding annuli which recur at 5 seconds Also the refractory interval feels as if it decreases as the induction session is extended These similarities suggest that the amorphous phosphenes are generated by stage 2 NREMS delta wave activity which is an activity governed by the reverberation of the cortical slow wave in thalamoshycorticothalamic circuits The cortical slow wave is referred to the LGN where it modulates the firing of visual relay cells in the laminae and since relay cells do not have local dendritic connections the expansion of a wave of depolarshyizations moving from one relay cell to the next across in the laminar surface will mirror at least in part the expansion of the cortical wave that is spreading contemporaneously through locally-connected cortical cells

PART III RETENTION OF CONSCIOUSNESS

In a normal transition to NREMS the volley of synchronous spindle bursts that marks the onset of stage 2 NREMS overwhelms the normal firing pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 137

of thalamocortical cells preventing their relay of afferent sensory signals and inducing a loss of consciousness21 But the loss of consciousness cannot be timed precisely using cortical EEG the thalamus is too remote for the onset of spindling to be reliably detected by scalp electrodes39 In experiments with cats where electrodes could be implanted in the thalamus researchers found that spindling often reached peak levels of activity in the thalamus-a level of activity consonant with stage 2 NREMS-at a time when the cortical EEG was still showing intermittent desynchronizations a pattern characteristic of the drowsy stage 1 transition not a fully-established stage 2 NREMS episode4o

In other words there is a short period of time in which the synchronous rhythms of stage 2 NREMS are installed in the thalamus but not in the cortex where cortical neurons continue to depolarize in response to afferent sensory signals

T his finding suggests a possible explanation for the authors ability to retain consciousness while spindle bursts are sweeping through the LGN if he is able to extend the duration of this time lag between

the onset of spindling in the thalamus and spindling in the cortex if he is able to stimulate the visual cortices in such a way that they continue to depolarize then he may be able to keep on processing visual signals-to remain visually aware-even after the non-visual thalamus and non-visual cortex become entrained by synchronous sleep rhythms The authors induction technique includes several behaviors which are known to enhance the responsiveness of visual neurons-eye movements attentive fixation and an attitude of expectancy

Effects of eye movements and attention on the LGN Sustained convergence causes periorbital proprioceptors to send excitatory feedback directly to the LGN41 Also convergence further enhances the excitability of geniculate cells by stimulating the superior collicus (SC) which sends its own excitatory signals to the LGN42-43 These signals from the SC are known to selectively enhance the excitability of visual relay cells that represent the periphery of vision44 We know in the authors case that the SC is being stimulated because he is able to keep on fixating an ability which would normally be lost during the transishytion to NREMS45 The ability to fixate can be retained however if the SC is stimulated (even if stimulated during NREMS)46

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 138

Effects of eye movement attention and expectancy on the primary visual cortex The PET study of mental imagery by Kosslyn et al 3 showed that even a baseline resting state of relaxed immobile expectancy can generate signifishycant increases in neuronal activity in the primary visual cortices Further increases can be induced by sustained eye movements

A sustained convergence will release a stream of ponto-geniculo-occipital (PGO) waves These PGO waves called eye movement potentials or EMPs last only as long as the eye movement1747 whereas the PGO waves associated with rapid-eye-movement sleep (REMS) fire continually for the duration of the REMS episode Both REMS-related PGO waves and EMPs have the same desynchronizing effect on the visual pathways they move through the LGN depolarizing the thalamocortical cells which relay the signals to cortical neurons The responsivity of neurons in the primary visual cortices is enhanced by the stimulation of PGO waves 1747-49 If the passage of EMPs causes the genicushylate relay cells and their cortical targets to depolarize regularly then a volley of 4 spindle bursts moving through the same pathways will register as just another series of depolarizations in effect the spindle bursts are processed by the visual system as if they were sensory signals sent from the retina rather than an event stimulated by endogenous mechanisms

T he impact of eye movements and ftxation on the parietal visual cortex Convergence and attentive fixation will also enhance the responsiveness of light-sensitive parietal visual neurons (PVNs) in area PG of the

posterior parietal cortex 50 In experiments where monkeys are trained to fix their attention on a screen-and to keep on fixating even if no targets appearshythe excitability of these light-sensitive PVNs increases by as much as 350 51

52-53Responsiveness is also facilitated by the angle of gaze Also area PG is the first region in the visual pathways containing individual neurons with the capacity to respond to large bilateral stimuli moving in opposite directions along the central meridians of vision (opponent vector motion) 853-55 Facilitation of PVNs in area PG has the effect of sensitizing the subject to bilateral opponent vector motion and this is especially true if the movement appears in the periphery of the VE 8

Intracortical ampliftcation and feedback to the LGN When PGO waves and signals from the SC arrive in the primary visual cortex they may be relatively weak however weak signals can be amplified by reverberating in large networks

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 139

of cortical cells linked by local projection 56 There are nine times as many excitatory links among cortical cells as there are projections from the visual cortex to the LGN an imbalance which suggests leads Suarez Koch and Douglas to propose that geniculate input provides only a minor fraction of the excitatory input the majority originating in neighboring and recurrently connected cortical cells57 If the excitabiliry of cortical neurons is slightly higher than normal then this process of amplification may continue even after the LGN signals that initiated the reverberation are no longer being transmitted by the LGN ( a hysteretic mode of operation) 57

Feedback from hyperexcited cortical neurons will stream back to the LGN via corticogeniculate projections which outnumber geniculocortical projections ten-to-one One effect of this feedback is that the LGN is

able to absorb large amounts of information flowing back from the cortex 58

As signals reverberate back and forth in thalamocorticothalamic circuits a matching process takes place those geniculate relay cells that fire in patterns consistent with the firing patterns of active cortical cells will have their responshysivity enhanced while those geniculate cells that fire in patterns not consistent with cortical cells will be suppressed 59

Preservation of consciousness by selective facilitation of the visual pathways By combining all of the facilitatory effects produced by the authors eye movements and attentive fixation-(l) stimulation of the LGN by feedback from periorbital proprioception both directly and indirectly via the SC (2) the release of PGO waves (EMPs) that facilitate neurons in the LGN and primary visual cortex as they pass (3) the facilitation of the primary visual cortex by a state of relaxed immobile expectancy (4) attentive fixation and angle of gaze that facilitate PVNs in area PG (5) intracortical amplification of signals received from the LGN and (6) corticogeniculate feedback that stimulates the LGN-we delineate a circuit of enhanced excitability that extends from the LGN through the post-geniculate visual heirarchy to area PG where signals are integrated into representations of objects

The hyperexcitability of neurons all along the post-geniculate visual pathways creates conditions in the visual cortices which are similar to those present during EEG-desynchronized states of waking and REMS Therefore neurons in the visual pathways are too excitable to be entrained by synchronous bursting

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 140

patterns when spindle waves move through them instead the spindle bursts stimulate visual neurons to depolarize and then recover as happens in response to afferent sensory signals during waking states It is important to note that for this to occur none of the constituent neuron assemblies is required to perform an abnormal operation the abnormality is a function of the authors intent to activate contemporaneously neuron assemblies that would not normally be co-activated

PART IV HYPNOTIC ANALGESIA

Manipulation of spatial attention as a method for alleviating pain sensations In a theoretical article on the neurophysiology of hypnosis Crawford and Gruzelier60 propose that variations in hypnotizability are function of variability in the efficiency of the frontolimbic (anterior) attentional system in humans high-hypnotizables are better able to sustain focused attention on a task and to ignore extraneous stimuli than are low-hypnotizables

I na related empirical study that compares the use of attention by subjects with high versus low hypnotizability Crawford Brown and Moon61 report that highly hypnotizable persons continue to show physiological reactivity

while cognitively not perceiving the painful stimuli Through disattentional processes they can dissociate themselves from the awareness of pain The authors phosphene induction behaviors-and the cutaneous analgesia he experishyences-appear to involve the same kind of behaviors that is a mobilization of frontolimbic attention used to withdraw attention from external stimuli and to concentrate it on internally-generated phosphene images This suggests the hypothesis that the mechanisms that generate phosphenes might also produce hypnotic analgesia There are several ways that visual signals and pain signals might interact to produce this analgesia

Competition between pain and vision signals for limbic registration The fully-developed sensation of pain requires integration of rwo kinds of informashytion Signals that encode the location and intensity of a noxious stimulus (nociceptive signals) are relayed via the thalamus to the somatosensory cortices which registers only the sensory-discriminative aspects of pain perception62 before reaching consciousness the nociceptive signals must be sent to the limbic

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 141

system where they are linked with signals from long-term memory that encode the affective significance the stimulus has acquired for that individual Studies of brain metabolism show this linking of somatosensory information with limbic associations takes place in the anterior cingulate (CG) and anterior insula62-64

PET studies also show that the anterior CG is activated when subjects shift their spatial attention in response to expectations as to where

66stimuli will next appear65- This is precisely what takes place during the state of immobile expectancy that induces phosphenes Since visual signals and nociceptive signals both require limbic enhancement which is only possible if they get access to the anterior CG there might be conditions in which the two types of afferent sensory signals have to compete for that access In a theoretical article on the mechanisms of attention Posner and Rothbart67

propose that visual signals can interfere with nociceptive signals by blocking access to the anterior CG As behavioral evidence they cite studies showing that when young infants make distress calls they can be distracted by the presentation of a new visual stimulus We have shown the evidence of such control at about three months Orienting to visual events can be employed to quiet or calm negative vocalizations However the distress appears to be maintained and reappears when the infants attention to the stimulus is reduced Caregivers also report the use or visual orienting to block overt manifestations of distress at about this age 67

The effects of disattention on the somatosensory cortices If there is a competition between visual signals and nociceptive signals for access to the anterior CG it is likely that the competition will be affected by the relative volume of signals received A recent study suggests that focusing attention on internally-generated visual stimuli may reduce the number of nociceptive signals relayed by the somatosensory cortices Drevets Burton Videen Snyder Simpson and Raichle68 have shown that the mere anticipation of a touch at a specific cutaneous site increases the flow of blood to those cortical somatosenshysory neurons that are linked with that site where touch is expected and decreases the flow of blood to neurons linked with sites where touch is not expected In this experiment the researchers designated touch as the behaviorally significant sensory stimulus but their findings suggest that the outcome could be reversed if the instructions were reversed if subjects were

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page J42

instructed to direct attention away from a cutaneous site where a noxious stimulus was being applied if they were instructed to relax close their eyes and concentrate on the play of phosphenes in the visual field as the behaviorally significant sensory stimulus then it would be reasonable to expect that the flow of blood would decrease to the somatosensory neurons linked with the cutaneous stimulus and that the flow of blood would increase to the visual cortices The decrease in blood flow to somatosensory neurons implies less neuronal activity which implies that fewer signals are being sent forward to the anterior CG than would have been sent if instead the subject were treating the touch as the behaviorally significant sensory stimulus If fewer pain signals arrive at the anterior it is reasonable to infer that the conscious experience of pain will be muted by the diversion of attention to internal visual stimuli

Differential impact of sleep rhythms in the visual and nonvisual thalamus There is another mechanism that might also contribute to the analgesic effect of inducing sleep rhythms PET studies show that

the thalamus is involved in the relay of nociceptive signals to the cortex63 although some confusion remains about which kinds of signals are relayed by which subregions in the thalamus62 One thalamic site clearly identified by anatomical studies as a relay for nociceptive signals is the ventroposterior lateral nucleus (VPL)69 If synchronous sleep rhythms are active in the thalamus we can reasonably expect that the VPL will itself be entrained by synchronous oscillations and that it will relay the sleep rhythms to somatosensory cortices Relay neurons in the VPL are not stimulated by feedback from eye movements and fixation as are relay neurons in the LGN which suggests that sleep rhythms may impede the relay of nociceptive signals via the VPL but not the relay of visual signals via the LGN

Brain waves associated with anesthesia and NREMS The hypothesis presented here-that consciousness can be preserved despite the presence of NREMS activity-is consistent with a recent report that the kinds of fast brain waves which are normally associated with conscious states are also present during NREMS and anesthesia two states which were thought to involve minimal brain activityJo Another recent study found that there is a close resemblance between the slow brain waves that appear during NREMS and those that appear during certain types of anesthesia71

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 143

bull bull bull

CONCLUSION

In this paper we have presented evidence supporting the hypothesis that phosphene images can be generated as an epiphenomena of thalamic spindle bursts and delta wave activity normally associated with NREMS The prereqshyuisites for inducing these sleep rhythm phosphenes are relaxed immobile expectancy sustained convergence and attentive fixation of an undifferentiated visual field Our hypothesis provides a necessary and sufficient explanation for the authors induction of phosphenes and perhaps also for the generation of phosphenes reported to appear spontaneously during the drowsy transition to sleep (hypnagogic states) during sensory deprivation or during certain kinds of prayer or meditation all of which involve a similar state of relaxed immobile expectancyJ2

CORRESPONDENCE Philip T Nicholson bull 52 Norfolk Road bull Chestnut Hill MA 02167

REFERENCES amp NOTES

1 M 1 Posner Modulation by Instruction Nature 373 (1995) pp 198-199 2 J Reissenweber E David amp M pfotenhauer Investigations of Psychological Aspects of

the Perception of Magnetophosphenes and Electrophosphenes Biomedizinische Tecknik 373 (1992) pp 42-45

3 S M Kosslyn W L Thompson 1 J Kim amp N M Alpert Topographical Representations of Mental Images in Primary Visual Cortex Nature 378 (I995) pp 496-498

4 P E Roland amp B Gulyas Visual Memory Visual Imagery and Visual Recognition of Large Field Patterns by the Human Brain Functional Anatomy by Positron Emission Tomography Cerebral Cortex 51 (1995) pp 79-93

5 H Benson The Relaxation Response (Morrow New York NY 1975) 6 ] H Schultz amp W Luthe Autogenic Training a Physiological Approach to Psychotherapy

(Grune amp Stratton New York NY 1969) 7 E Jacobson Progressive Relaxation (University of Chicago Press Chicago IL 1938) 8 M A Steinmetz BC Motter C] DuffY amp V B Mountcastle Functional Properties

of Parietal Visual Neurons Radial Organization of Directionalities Within the Visual Field Journal ofNeuroscience 71 (1987) pp 177-191

9 R R Edelman Magnetic Resonance Imaging of the Nervous System Discussions in Neuroscience 71 Elsevier Science Amsterdam (I990) also J H Newhouse amp ] I Wiener Understanding MRI 1st Ed (Little Brown Boston MA 1991)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 144

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

RECEDING ANNuLI EVOKED BY MAGNETIC REsONANCE IMAGING (MRI)

A s a patient undergoing an MRI scan the author observed an unusual sequence of receding annuli He was not relaxed as in a normal induction but rather anxious about his medical condition and about

being confined in the narrow MRI tube To keep calm he concentrated on breathing slowly and stared straight ahead While the sound of MRI machine was audible the author observed a stream of receding annuli that differed from the usual sequence (self-induced and hypnagogic) in three ways (I) the MRI annuli did not terminate at 4 cycles but continued for as long as the author kept his attention focused (2) the MRI annuli were only yellowshygreen in color even though in other inductions the fill-in disk had already changed from green to blue and (3) MRI annuli completed their trajectoshyries in half the normal time disappearing in 2 seconds instead of 4 An interval of 2 seconds between radio pulses is often selected as optimal interval for capture of the signals emitted by hyperexcited atoms in the subjects body

10during the precessional relaxation 9- These observations suggest that energy released in the wake of the radio bombardment during MRI moves through the LGN as a standing wave in the same way that spindle bursts move but that the 2-second duration of the MRI wave is not long enough to activate the neurons that generate a blue sensation

THE ANESTHETIC EFFECT ASSOCIATED WITH SELF-INDUCED

PHOSPHENES

On several occasions the author has preferred to undergo minor surgery without local anesthetic and to rely instead on autohypnotic analgesia-for example during extraction of an infected abscess from the back during laser surgery to

remove keloids and during the filllng of dental caries His experience on a recent occasion when a dentist had to abrade the surface of six teeth with damaged enamel in order to create a strong bonding surface are worth describing here because the experience implies that spindle waves can be induced even during a state of high physiological arousal For this appointshyment the author arrived in the office too late to hypnotize himself in advance

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 121

so he had to begin the normal induction procedures after the dental work was already underway

A s the dentist worked on the first tooth the author experienced apprehension sharp sensations of pain and an involuntary tensing of the large muscles of the body with each application of the drill As

the author kept his eyes converged and his attention focused on the center of the visual field the involuntary tensing in response to pain alternated with a precipitous relaxing of those same muscles immediately after the stimulus With the repeated relaxation came a sense of relief and of letting go that amelioshyrated the pain The pain-driven relaxation was much stronger than the relaxation that normally accompanies the authors self-induction of phosphenes and the alternation of a pain-driven tensing on one hand and the distancing effect of focusing attention on the visual field on the other hand resulted in a rapid dissociation from all external and internal stimuli including a signifishycant amelioration of painful sensations

Most striking is the fact that by the time the dentist reached the third toothshyafter only a few minutes of this pain-driven self-hypnosis-the author saw a normal sequence of 4 receding annuli followed by swirling clouds of amorphous expanding phosphene even though the dentist was still using the drill contemporaneously This experience suggests that thalamic sleep rhythms can be voluntarily induced even when the subjects level of physiological arousal is high

SIMILARITIES WITH ATTENTION-INDUCED PHOSPHENES

REpORTED BY OTHER OBSERVERS

Taxonomies of phosphene images always include examples of simple geometric phosphenes with circular or semi-circular shapes (disks annuli or crescents) as

14well as formless phosphene mists 11 - There are also a number of anecdotal accounts that are relevant for example Friedman an opthamologist who studied entoptic images by introspection describes a similar sequence of annuli induced by sustained inward concentration Circular waves of blue color may be seen in the dark by the dark adapted retina They start at the

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 122

periphery and move inward toward the macula as a concentrically contracting solid circle disappear at the macula and begin again at the peripheryl)

A valuable but often-neglected resource of information about phosphene imagery is presented in the literature of religious mysticism Many mystics reported having seen translucent colored lights while absorbed in prayer or meditation A list of descriptions excerpted from self-reports is presented in Table 1 (These excerpts are representative of phosphene images that appear during states of calm and inward-oriented concentration they do not include images associated with paroxysmal raptures) These phosphene images exhibit a relatively limited set of shapes and colors the shapes are either circular (eg rings disks wheels suns) or formless (eg mists snow smoke) and the colors are usually a variant of either green or blue The phosphene visions of mystics display shapes and colors that are comparable to the images described by the author this and the many similarities in the behaviors used to induce phosphenes suggest that both sets of phosphenes have a common etiology

DISCUSSION

Whether the author uses self-hypnosis to induce phosphenes or experishyences them as hypnagogic images the threshold sequence of receding annuli has the same characteristics In both these

instances the antecedent behaviors involve a state of low physiological arousal combined with mental withdrawal from external stimuli These parallels suggest the hypothesis that phosphene displays are related to sleep-wake transitions

PART I RECEDING ANNULI AND THALAMIC SPINDLES

Mechanisms controlling the transition from waking to NREMS Based on the work of several research teams16-20 a consensus scenario for the generation of NREMS has emerged In this scenario NREMS is the product of three brain rhythms that interact with each other in thalamocorticothalamic circuits During the drowsy transition to sleep which in humans is called stage l NREMS the low voltage activity in the cortical electroencephalograph (EEG) still shows a pattern of intermittent desynchronization The polarization of

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 123

Table I Excerpts from self-reports of light visions by religious mystics

HEBREW MYSTICS the appearance of the wheels was like the gleaming of beryl and the four had the same form

their construction being something like a wheel within a wheel Ezekiel like a dome shining like crystal spread out about their heads And above the dome something

like a rhrone in appearance like sapphire Ezekiel a round Iodder like a full sphere rolling back and forth before him bright blue R Abulafia A glowing light clear brilliance A purple light that absorbs all lights R Moses de Leon

HINDU AND BUDDHIST MYSTICS a perfectly round beautiful deep-blue shape of a size appropriate to the center of a mandala as

if exquisitely painted of extreme c14rity Tsong Khapa a luminous revolving disc studded with lights a lotus flower in full bloom Gopi Krishna both my eyes became cemered When this happened a blue light arose in my eyes like

a candle flame without a wick and stood motionless in the ajna chakra S Muktananda

MUSLIM MYSTICS [like] chandelierssublime lights [like] stars moon or the sun Sharafuddin aI-Maneri its color is deep blue it seems to be an upsurge like water foom a spring Najmoddin Kobra visualize yourself as lying at the bottom of a well [looking up at the light of the opening] and

the well in lively downward movement Najmoddin Kobra the color green is the suprasensory uniting all the suprasensories Alaoddawleh Semnani the light rises in the Sky of the hean taking the form of light-gilling moons Najm Razi

CHRISTIAN MYSTICS his own state at prayer resembles a sapphire it is as clear and bright as the sky Evagrius descending like a bright cloud of mist like a sun round as a circle Simeon Neotheologos saw something in the air near him He did not understand the rype of thing but in some ways

it appeared to have the form of a serpent with many things that shone like eyes although they were not eyes Ignatius of Loyola

the soul puts on a green amilia [cape worn on shoulders beneath armor] John of the Cross [the almilla is like a helmet which] coverS all the senses of the head of the soul It has one

hole rhrough which the eyes may look upwards John of the Cross a round thing about rhe size of a rixdaier all bright and clear with light like a crystal H Hayen I saw a bright light and in this light the figure of a man the color of sapphireblazing with a

gentle glowing fire the three were in one light Hildegard von Bingen saw a b14zing fire incomprehensible inextinguishable with a flame in it the color of the sky

Hildegard von Bingen saw placed beneath her fuet the whole machine of the world as if it were a wheel She saw herself phced

above it her eyes of contemplation magnetized towards the incomprehensible Beatrice of Nazareth I saw the eyes I do not know if I was asleep or awake Angela of Foligno kind of sunlit winged being like a childs head beneath two little wings Abbess Thaisia laquobullbull round patterns small circles would expand and eventually dissipate only to be followed by other small

circles of light Philip St Romain an extraordinary circle of gold light pulsating against a deep violet background There were

always four or fille As soon as one would fode another would appear Philip St Romain

middotItalics added to mark words referring to (l) rings appearing in sets of four (2) amorphous shapes such as clouds or flames (3) circular or eye-like shapes (4) colors from the center of the visible spectrum (gold yellow yellow-green green bluish green) and (5) colors from the lower end of rhe visible spectrum (blue purple violet)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 124

cell membranes (Vm) has already begun to drop (hyperpolarize) in the thalamic reticular nucleus (RTN) a thin sheath of GABAnergic inhibitory neurons that acts as a pacemaker When the Vm of RTN cell membranes drops to approximately V m -60 millivolts (mV) RTN cells stop firing single spikes which are associated with waking states and instead begin firing highshyamplitude 7-14 Hertz (Hz) spike-bursts These bursts wax and wane over 1 to 3 seconds-hence the name spindle -and recur at 3 to 10 seconds Spindle volleys are relayed across the cortical mantle by thalamocortical (TC) sensory relay cells In human studies the primary criterion for onset of the first fullyshyestablished episode of NREMS or stage 2 sleep is the presence of globalized spindles in the cortical EEG

When spindle bursts from the RTN stimulate TC cells to fire in synchrony this synchronous bursting pattern overwhelms the normal capacity of TC cells to relay afferent sensory signals The loss of consciousness at the onset of stage 2 NREMS is thought to be caused by this blocking effect 21

While the RTN is firing spindle bursts through the thalamus another process is activated in the cortex large numbers of cells across the cortical mantle begin to oscillate at a very low frequency laquo 1 Hz)

The cortical slow rhythm referred back to the thalamus via corticothalamic circuits intensifies the hyperpolarizing effect of the RTN spindle bursts on TC cell membranes When V m -75 mV the TC cells begin to generate their own intrinsic calcium currents which further increases hyperpolarization At V m -90 mV the RTN neurons stop firing spindle bursts The TC cells continue to fire low-threshold calcium spikes in patterns which are controlled by the cortical slow rhythm The interaction of these two oscillations generates the delta waves (1 to 4 Hz) which are associated with stage 2 NREMS

In a study of sleep rhythms using the cortical EEG Uchida Atsumi and Kojima found that the mean number of spindles required to induce delta wave activity (that is to induce Vm = -90 mY) is 478 plusmn 162 spindles (from 3 to 7 spindles)22 The mean number of spindles in a volley remains the same for a single individual over multiple trials

Based on the consensus scenario for generation of NREMS we can predict that a phosphene image generated as an epiphenomenon of a thalamic spindle

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 125

Table II Dara show rhe degree of correspondance berween rhe pulse panerns of rhalamic spindles based on intracellular research and rhe sparioremporal panerns of receding annuli phosphenes induced by rhe author using a rechnique of self-hypnosis

Receding annuli phosphenes Thalamic spindle bursrs

Mean number of signals 4 annuli 487 (plusmn 16) bursrs

Sparial exrension vs Thin band 1 - 3 seconds durarion of signal ( 05 -15 cm)

Periodicity of signals 5 seconds 3 - 10 seconds

Simultaneity in LGNs Yes Yes

Point of entry Peripheral VF Ventral amp lareral LGN

Trajecrory Bilareral concentric Unknown

Rare of flow Cons rant rare Unknown

Signal-ro-noise rario High High (shorr bursrs) (sharp brighr discrere)

Termination of sequence Mrer 4 signals Mrer 487 (plusmn 16) signals

will present the following characteristics (1) a high-definition burst-like signal (2) that recurs within 3 to 10 seconds (3) that follows a trajectory compatible with having entered the LGN from the RTN (4) that has a predictable mean for the individual subject and a range that falls somewhere between 2 to 7 annuli and (5) that the spindles will terminate automatically

The temporal patterns of receding annuli and thalamic spindle bursts are similar Table II illustrates the close match between the timing of receding annuli phosphenes and thalamic spindle bursts The most striking similarities are the mean number of signals required to induce termination (4 annuli versus 487 spindles) and the interval between signals (5 seconds for annuli versus 3shyto-lO seconds for spindle bursts) Neither alpha theta nor beta waves present this kind of stereotyped temporal pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 126

T he spatial features of receding annuli are functions of geniculate anatomy A spindle burst moving through the LGN to the cortex will acquire certain distinctive spatiotemporal characteristics because of the

unique curvilinear and laminar anatomy of the LGN A drawing of a macaque LGN based on a clay model constructed by Le Gros Clark23 is shown in Figure 3 The primate LGN is composed of six sheets of cells or laminae that fold over a central hylus In macaques the hylus rises steeply as it extends rostrocausally forming a high arch at the posterior pole in humans the hylus is much more shallow but the functional anatomy is thought to be essentially

23 24the same in both cases - The geometry of the arch forces each lamina to bend so as to constitute in effect one-half of a conical surface and each lamina with its hemi-conical shape contains visual relay cells representing the contralatshyeral half of the visual field (VF) Operating as a pair the complementary hemishycones of the right and left LGN form the functional equivalent of a single conical surface which represents the entire VE This conical geometry of the paired LGNs means a burst of otherwise formless excitation will acquire a distinctive shape as it propagates through the laminae of the LGN Imagine a horizontal section moving along the surface of a cone from base to apex that moving section forms an annulus that shrinks in diameter as it approaches the apex but retains its annular symmetry throughout its trajectory

Figure 3 also includes drawings that show how Connolly and Van Essen24

converted the 3-dimensional structure of lamina 6 the largest and most dorsal layer into a 2-dimensional map Connolly and Van Essen used data obtained by Malpelli and Baker25 to superimpose a grid that specifies the areas in lamina 6 that contain TC cells representing various degrees of isoeccentricity in the VE We will use this map at a later point to show how the movement of a spindle wave through a pair of LGNs correlates with what appears in the VE

The location of the RTN relative to the LGN is also shown in Figure 3 The RTN spindle pacemaker is a thin sheath of GABAnergic inhibitory cells that extends along the surface of the whole posterior ventral thalamus not just the LGN This extension brings the RTN into close proximity with the portion of the LGN (lateral wing) that protrudes out from the main body of the thalamus Some of RTN wraps around and beneath the ventral edges of the LGN26 The RTN comes closest to the LGN in two areas along the ventral edges of the longest laminae (lamina 6 and 1) and along the edge of the lateral

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 127

DORSAL POLE DORSALPOIEA B

L1 L4 L3 L

DORSAL POlE DORSAL POIE (FOVEA)

G LATERAL WING

25

DORSAL POL (FOVEA)

10 _DIAL

20 WING

~

wing These areas contain TC cells that represent the far periphery of the VE If a spindle burst enters the LGN at locations where laminae are in closest proximity to the RTN-along the ventral edges-then the discharge of TC cells will begin in the most ventral portions of the laminae the regions that represent the far periphery of the VE This matches the phosphene sequence observed by the author

Our hypothesis about how this proximity between RTN and LGN affects the trajectory of spindle waves is illustrated in Figure 4 We propose that it is not possible for the author to observe a thin annulus of phosphene sweeping in from all 3600 of the peripheral VF unless spindle bursts exhibit the following

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 128

Figure 3 [facing page Drawings of primate geniculate anatomy and functional anatomy relevant to the generation ofphosphenes (A) Anterior view ofa macaque monkey LGN based on a clay model reconstruction by Le Gros Clark 23 (B) Posterior view ofthe same model showing 6 laminae folded over a central hylus to form lateral and medial wings with the hylus arching steeply upward near the posterior pole to shape the laminae into layers of hollow half-cones nested together Note that the lateral wing of the LGN is slightly larger than the medial wing so that in situ the lateral wing protrudes out from the main body of the thalamus creating a small knob visible during dissection 26 (C) Schematic drawing of an oblique section through median axis (also adapted from Le Gros Clark13 showing how the laminae fuse together at the anterior pole The afferent ganglion cell axons that form the optic tract (OT) penetrate through the anterior surface to reach their target relay cells in the laminae (D) Drawing of the most dorsal lamina-layer 6--separated from the rest of the LGN The geometric shape is a hollow half-cone so that right and left LGNs placed back-to-back form in effect a single cone Note also the position ofthe RTN shown here as a striped bar relative to lamina 6 The position of the striped bar shows that the RTN makes direct contact with lamina 6 at the edge ofthe lateral wing and also along the ventral edges (E - F) Schematic drawings adapted from Connolly and Van Essen24 that show how a 3-dimensional lamina-lamina 6--can be transformed into a 2-dimensional triangular figure lamina 6 is removed and its wings unfolded (E) creating a slightly asymmetric triangular figure (F) which is adjusted to an oblong shape (G) in order to superimshypose a grid matrix with minimal distortion The grid plots locations of TC cells that represent various isoelevations and isoazimuths in the VF locations derived from the experimental observations published by Malpeli and Baker 25 Note the relatively large amounts of laminar surface allocated to central vision (0 0

- 30 0) as compared

to peripheral vision (30 0 - 80 0)

characteristics (1) Spindle bursts must move simultaneously through both geniculate nuclei This pattern of movement is consistent with anatomical studies in primates that found axonal projections linking the right and left RTNs27-28 and with experimental studies in cats that found spindles appearing simultaneously in both right and left thalami 29 (2) Spindle waves must enter the ventral edges of the LGN first and move ventrodorsally in a highly coherent pattern-moving in effect as a standing wave This pattern of movement is consistent with in vitro experiments using sagittal slices from a ferret LGN where spindle waves originated spontaneously at the edge of a slice in an area which contains cells that represent peripheral vision then propagated toward that area of the slice containing cells that represent central vision in the ferret 3o

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 129

VF

PG BIlateral receptive lleJd of PVN YI(j Inward dmKooflality Adapled

0-- from Mortgr at at (1987)

V1

ibull t bull

RTN t t t t t t 1middot3 SECOlO BURSTS OF 7middot14 HZ SPiKES RECURRNG EVERY 3 10 SECONDS

To our knowledge the LGN is the only anatomical structure in the visual system that has the capacity of passively forcing a wave of excitation to flow across a conical surface thereby generating the sensation of a phosphene annulus that retains its symmetry as it shrinks in diameter The retina has a circular anatomy but it is not likely that the mechanical deformation of the retina would produce a wave that began simultaneously in all 3600 of the retinal rim nor that the symmetry of annular wave would be preserved as it flows inward toward the foveal region

The hypothesis presented here-that there is a structure in the visual system that imprints a conical shape on standing waves that move through it-explains

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 130

Figure 4 facing page Schematic drawing of contemporaneous events in selected regions of the visual processing hierarchy (A) The left and right RTNs fire spindle bursts simultaneously (B) The bursts pass through the right and left geniculate laminae as standing waves of depolarization entering from the ventral edges and moving ventrodorsally in parallel In order for the phosphene annulus to appear to be flowing at a constant rate the spindle wave flowing through the LCN must expand in width as it ascends ventrodorsally so that by the time the fill-in disk appears-when the center 30deg of the VF is covered by the phosphene annulus-the spindle wave must have expanded enough to activate relay cells in the most dorsal 50 of lamina 6 (C) Signals representing two complementary hemi-annuli are kept separate in the primary visual cortices (area VI) (D) Signals representing the two hemi-annuli are integrated into signals of a single annulus when they reach area PC in the posterior parietal cortex where the receptive fields of single parietal visual neurons have the capacity to register bilateral signals that exhibit opponent vector movement (that is signals converging from opposite directions along the central axes-as if an object were moving away from the viewer)46 Neurons in area PC also integrate wavelength (color) signals from the extrastriate visual pathway with signals about brightness motion and depth from the parietal visual pathway to compose a representation of an object in space-in this case of an annulus that appears to recede 32

the authors experience during MRI when he observed a continuous succession of receding annuli every 2 seconds in this view the energy of the electroshymagnetic bombardment when released during precessional relaxation flows through the geniculate laminae in the same way that the RTN spindle bursts do that is as a standing wave and thus the visual epiphenomenon is the same in both cases if the subject keeps the eyes focused straight ahead and the attention fixated In a study of phosphenes evoked by electricity in conjunction with hallucinogenic drugs Knoll Kugler Hofer and Lawder found that each subject sees specific kinds of phosphene at different frequencies and that these frequency-specific images are stable enough to be reproduced after six months31

They conclude that the tunability of the electrical stimulation frequenshycies within the EEG range to various definable phosphenes requires the existence of a resonance system One mechanism contributing to that resonance system may be the functional anatomy of the LGN

The colors of receding annuli as functions of geniculate laminar anatomy The colors of receding annuli phosphenes are consistent with the patterns of discharge spindle waves can be expected to stimulate as they move through

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 131

geniculate laminae As shown in Figure 5 the six laminae differ (1) in the types of wavelength signals relayed (2) in physical size and (3) in the area of the VF represented 24-25 Only 4 out of 6 laminae Cparvocellular layers 3shy6) contain TC cells that relay wavelength signals the other 2 laminae (magnocellular layers 1 and 2) do not encode wavelength Among parvocelshylular laminae only lamina 6 the longest and most dorsal layer contains TC cells that can represent the far periphery of the VF (from 800 to 50deg of isoeccenshytdeity) therefore when the spindle wave enters the peripheral VF only those wavelengths relayed by lamina 6 will participate in composing a cortical lightness record (See Zeki)32

I n lamina 6 ganglion cell axons arriving from the retina carry two kinds of wavelength signals (1) center-ON signals from medium-wavelength cones (M-cone center-ON) and long-wavelength cones (L-cone centershy

ON)33-35 Using the cone spectral sensitivity curves (adapted from Marks et al 36) we average the wavelengths that elicit maximal responses for M-cones (535 nanometers) and L-cones (520 nm) which yields a mean wavelength value of 550 nm In humans this wavelength generates a sensation of green or yellowshygreen the sensation observed by the author

As the spindle burst moves ventrodorsally it reaches the dorsal areas in the geniculate laminae which contain TC cells representing the central 0deg to 20deg of isoeccentrieity in the VE All 4 parvocellular laminae have TC cells which are potentially capable of representing this central region of vision but the authors observation that the color of the filling-in disk changed from green to blue implies that in the early years of phosphene induction the spindle wave must have remained close to the surface of the LGN stimulating only laminae 5 and 6 which generates a sensation of yellow-green When the fill-in disk was observed to change color from green to blue the spindle wave must have been rechanneled so that it began to penetrate below laminae 5 and 6 and to activate laminae 3 and 4 the only laminae that relay blue-sensitive signals (Sshycone center-ON signals)3 In light of the authors MRI experience it seems likely that a spindle wave requires a minimum of 2 seconds to reach the blueshysensitive cells of laminae 4 therefore during MRI when the receding annuli disappeared after 2 seconds half the normal duration the fill-disk had a green color even though it had long since change to blue in other induction settings with a 4-second trajectory

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 132

A REPRESENTATION OF THE VISUAL FIELD IN EACH LAMINA

orooqUtftc O-u OCIJ1SALfIOLI (I01flAj

0

10

20

30

40 n50 Of

60

70

20 loO 1Mgr_ II~ o UIpoundAS65 mn1MY-o actlvncL ~~~r

Jll-COMcetlImiddot~

II LAYERSU 3 GatQYancetl~ (1) ucon ceom-oyenF (2)l~cen()FF 3) ~ cenloH

II~ cng1loqctWIIIfNla

iICINe -- (t81Otdb1t1d~OH (2)~

80

B CONE SPECTRAL SENSITIVITY CURVES

S-COHS

WAVIlLllNG1llS OF UGHT IH NANOMllTERS (NM)

Figure 5 Phosphene color as a function of ganglion cell distribution in parvocellular laminae (Aj Schematic drawing ofthe proportion ofthe VF represented in each laminae The proportions shown here are based on the work of Connolly and Van Essen24 The

far periphery of vision (50 0 to 80 0 of isoeccentricity) is represented in only two laminae-laminae 1 and 6-and of these two only lamina 6 is a parvocelLular lamina capable ofencoding wavelength signals Therefore only those wavelengths relayed by lamina 6 will participate in forming a cortical lighmess record for the far periphery of the VP (B) Cone spectral sensitivity curves (adapted from Marks et al)36 Using these cone sensitivity curves we can estimate the sensation stimulated by a spindle wave moving through lamina 6 by averaging the wavelengths that elicit maximal responses for M-cones (535 nanomeshyters) and L-cones (520 nm) which yields a mean wavelength value of550 nm In humans this generates a sensation of green or yellow-green the sensation observed by the author when the receding annulus enters at the far periphery of the VP For a calculation of the cortical lightness record when a spindle wave moves through 20deg to 0deg ofthe VF stimulating all 4 parvocelfular laminae see the text and Figure 6

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 133

Once the spindle wave penetrates to laminae 3 and 4 it may activate all 4 parvocellular laminae stimulating TC cells to send contradictory wavelength signals for the same retinotopic location the signals sent from laminae 4 and 3 will encode blue light (S-cone center-ON plus M-cone center-OFF and Lshycone center-OFF) while the signals sent from laminae 5 and 6 encode yellowshygreen light (M-cone center-ON plus L-cone center-ON) This kind of contrashydiction does not occur in normal retina-based perception where light energy striking the retina is structured by the retinas center-surround and colorshyopponent organization to encode only one set of wavelength signals for each spatial locus 32 In Figure 6 we estimate the cortical lightness record that results when contradictory wavelength signals compete to be represented in consciousshyness Our calculations suggest that the outcome will be a mean wavelength which in humans elicits a dark blue or violet sensation

PART II AMORPHOUS PHOSPHENES amp THALAMIC DELTA ACTMTY

M echanisms controlling the transition from spindle bursts to delta activity In the consensus scenario for the generation of NREMS16-20 we noted that the RTN shifts to firing spindle bursts

when polarization of thalamic cell membranes drops to V m = - 60 mV At the same time cortical cells begin oscillating with a synchronous slow rhythm laquo 1 Hz) Both processes further decrease the Vm of TC cell membranes When Vm = - 75 mY TC cells begin to generate their own intrinsic calcium currents which also decreases V m At V m = - 90 mV RTN neurons stop firing spindle bursts At the same time the TC cells begin firing low-threshold calcium spikes in alternation with after-hyperpolarizations (LTS-AHP) Because sensory relay neurons in the LGN are not linked to one another by locally projecting axons the firing of one TC cell does not excite its neighbor However a lack of local connectivity does not mean that TC cells occupying the same laminae release their AHP-LTS calcium spikes in a random distribshyution rather spikes are released simultaneously by groups of cells in synchrony with the advent of the cortical slow wave In effect the distribution of LTSshyAHP spikes firing in the LGN is determined by the spatial propagation of the cortical slow wave Thus the delta wave (1 to 4 Hz) activity detected by cortical EEG during NREMS is a product of the interaction between the AHP-LTS calcium spikes released by TC cells and the cortical slow rhythm

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 134

CORTICAL PROCESSING OF CONTRADICTORY

WAVELENGTH SIGNALS

KEY _ Cells firing

cJ Cononol firing

Assume that as a spind6e wave moves through the LGNlt fires simultaneously aU the TC cells that represent a particular reUnoshytopic locus (x y) in each of the six laminae As a result cortical cells engaged In the higher level processing of visual signals will receive more wavelength signals representing retina locus (x y) than are generated by normal perception laquo and some of these afferent wavelength signals may contradict other signals arriving simultaneously

CORTICAL LIGHTNESS RECORD SlgnalSell

Intemal contradictions not congruent wilt pre

SmiddotON eristing neuron neta

s bullbull M-ON LmiddotON

3 bullbull M-OFF + L-OFF

a-ON 12

ROD-ON

No Internal eonlradlemiddot

--------1I =~8b~~~~~~~t signals

3+4

~ --OFF Excludes 6 Of 7 $J9n18

1+2 B-ON I

IWmiddotHmiddotI Signal Sell

1111111 No Intern1 conlrfldlcshy lion

Exelvdta 4 out of 7 efshy

bullbullbull bullbullbull ferant signals

No Intern1 contradic_ tionnee S-ON BshyOH and ROO-ON can all be coacllve at low lImlnance levels nef Ihe rod-eone break

ExchJde$ only 2 Ollt of 7 afferent signals

Figure 6 Selection of competing wavelength signals based on neuronal group selection This thought experiment is based on Edelman sconcept ofneuronal group selection 73 We assume that all possible combinations ofsignals will form sets and that all signal-sets will compete to make the most efficient match with pre-existing neuromd networks that have been forged over years ofnorma reti1U1-based perception We also assume that pre-existing neural networks are most likely to expedite those sets that satisfY 2 criteriI (J) the signals in a set do not contradict each other and (2) fower signals are excluded than in the other sets that satisfY the first criterion In our analysis Set 4 wins the competition because it does not contain internal contradictions and excludes fower signals (2 out of 7) than Set 3 excludes (4 out of7) It is not an internal contradiction that Set 4 contains both rods and cone Signtlls in normal retina-based perception when luminance levels approach the rod-cone break S-cone center-ON receptors send signas as do rod receptors and there is even evidence that rod activity may actually drive S-cone activity even after luminance levels foIl below the rod-cone break74 To calculate the cortical lightness record for Set 4 we average the wavelength that elicits maximal responses foom rods (511 nm) and for Sshycones (430 nm) which yields a mean wavelength of 470 nm which in humans results in a dark-blue or violet sensation

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 135

The cortical slow rhythm is an example of a generic pattern of neuronal excitashytion that occurs in large networks of neurons linked by local projections A recent experiment by Maeda Robinson and Kwana38 shows that networks of locally-connected neurons spontaneously generate periodic synchronized bursts of calcium transients that propagate across the network in an expanding spatial wave a pattern that represents a stable mode of firing towards which these neuronal networks relax following perturbations for example by electronic stimulation or by drugs Understanding the characteristics of these waves is an important prerequisite to understanding the mechanisms that produce the amorphous phosphene images as a visual epiphenomenon

To study the spontaneous periodic synchronized bursts the researchers prepared cultures of dissociated cortical neurons and allowed them to mature for several days in vitro (DIV) After 3 to 4 DIV when concenshy

trations of extracellular magnesium were low electrodes began to detect spontaneous synchronized bursts of low frequency calcium transients (between 01 and 1 Hz) that originated in different locations on the sheet every 10 to 20 seconds and spread across the sheet of cells at a relatively slow speed averaging 50 mmsecond The researchers could not predict where a wave would originate or where it would expand rather the initiation and expansion of waves was generated by spatial and temporal summation of a continuous random background of synaptic inputs including miniature spontaneous synaptic events but the pattern was not random since waves propagated sequentially from electrode to electrode as each local group of neurons charges up its neighboring nontefractory areas rather than in a random sequence of regions38

The excitability of the cells in the sheet determines the probability first that there will be a synchronous burst and second that it will spread in a particshyular direction Cells become more excitable as the cultures mature which means the refractory intervals between successive bursts were much shorter in mature cultures (gt 30 DIV) than in early cultures laquo 7 DIV) Some cells became so insensitive to inhibition that they continued to fire bursts even when extracellular concentrations of magnesium were relatively high Finally there were refractory periods of 5 to 10 seconds during which no bursts occurred even when an electrical stimulus was applied This refractory interval for cultured networks is slightly longer than the refractory interval observed of the cortical slow wave in vivo which 25 to 4 seconds 18- 19

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 136

Based on the observations about cortical slow waves we can predict that phosphenes generated as epiphenomena of delta wave activity will present the following signal characteristics (1) signals that appear at unpredictable locations in the VF (2) signals that expand and diverge asymmetrically following unpredictable trajectories which may encompass large areas of the VF (3) signals that move relatively slowly (50 mmsec) (4) signals that recur with a period of 2 to 4 seconds reflecting entrainment by the cortical slow wave (5) signals that do not terminate automatically after a predictable number of cycles

The spatial patterns of phosphene mists and thalamic delta waves are similar The spatiotemporal characteristics of amorphous phosphenes match the pattern of wave propagation associated with periodic spontashy

neous synchronized bursts in large neuron networks the amorphous phosphenes enter the visual field at unpredictable locations expand and diverge asymmetrically with a slow steady rate of flow follow trajectories that are unpredictable and exhibit a refractory interval The amorphous mists do appear to have a periodicity although the author is unable to sustain the vision while also counting the seconds therefore he is unable to determine if it compares to the period of the cortical slow wave (25 to 4 seconds) but his impression is that it feels roughly the same as as with receding annuli which recur at 5 seconds Also the refractory interval feels as if it decreases as the induction session is extended These similarities suggest that the amorphous phosphenes are generated by stage 2 NREMS delta wave activity which is an activity governed by the reverberation of the cortical slow wave in thalamoshycorticothalamic circuits The cortical slow wave is referred to the LGN where it modulates the firing of visual relay cells in the laminae and since relay cells do not have local dendritic connections the expansion of a wave of depolarshyizations moving from one relay cell to the next across in the laminar surface will mirror at least in part the expansion of the cortical wave that is spreading contemporaneously through locally-connected cortical cells

PART III RETENTION OF CONSCIOUSNESS

In a normal transition to NREMS the volley of synchronous spindle bursts that marks the onset of stage 2 NREMS overwhelms the normal firing pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 137

of thalamocortical cells preventing their relay of afferent sensory signals and inducing a loss of consciousness21 But the loss of consciousness cannot be timed precisely using cortical EEG the thalamus is too remote for the onset of spindling to be reliably detected by scalp electrodes39 In experiments with cats where electrodes could be implanted in the thalamus researchers found that spindling often reached peak levels of activity in the thalamus-a level of activity consonant with stage 2 NREMS-at a time when the cortical EEG was still showing intermittent desynchronizations a pattern characteristic of the drowsy stage 1 transition not a fully-established stage 2 NREMS episode4o

In other words there is a short period of time in which the synchronous rhythms of stage 2 NREMS are installed in the thalamus but not in the cortex where cortical neurons continue to depolarize in response to afferent sensory signals

T his finding suggests a possible explanation for the authors ability to retain consciousness while spindle bursts are sweeping through the LGN if he is able to extend the duration of this time lag between

the onset of spindling in the thalamus and spindling in the cortex if he is able to stimulate the visual cortices in such a way that they continue to depolarize then he may be able to keep on processing visual signals-to remain visually aware-even after the non-visual thalamus and non-visual cortex become entrained by synchronous sleep rhythms The authors induction technique includes several behaviors which are known to enhance the responsiveness of visual neurons-eye movements attentive fixation and an attitude of expectancy

Effects of eye movements and attention on the LGN Sustained convergence causes periorbital proprioceptors to send excitatory feedback directly to the LGN41 Also convergence further enhances the excitability of geniculate cells by stimulating the superior collicus (SC) which sends its own excitatory signals to the LGN42-43 These signals from the SC are known to selectively enhance the excitability of visual relay cells that represent the periphery of vision44 We know in the authors case that the SC is being stimulated because he is able to keep on fixating an ability which would normally be lost during the transishytion to NREMS45 The ability to fixate can be retained however if the SC is stimulated (even if stimulated during NREMS)46

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 138

Effects of eye movement attention and expectancy on the primary visual cortex The PET study of mental imagery by Kosslyn et al 3 showed that even a baseline resting state of relaxed immobile expectancy can generate signifishycant increases in neuronal activity in the primary visual cortices Further increases can be induced by sustained eye movements

A sustained convergence will release a stream of ponto-geniculo-occipital (PGO) waves These PGO waves called eye movement potentials or EMPs last only as long as the eye movement1747 whereas the PGO waves associated with rapid-eye-movement sleep (REMS) fire continually for the duration of the REMS episode Both REMS-related PGO waves and EMPs have the same desynchronizing effect on the visual pathways they move through the LGN depolarizing the thalamocortical cells which relay the signals to cortical neurons The responsivity of neurons in the primary visual cortices is enhanced by the stimulation of PGO waves 1747-49 If the passage of EMPs causes the genicushylate relay cells and their cortical targets to depolarize regularly then a volley of 4 spindle bursts moving through the same pathways will register as just another series of depolarizations in effect the spindle bursts are processed by the visual system as if they were sensory signals sent from the retina rather than an event stimulated by endogenous mechanisms

T he impact of eye movements and ftxation on the parietal visual cortex Convergence and attentive fixation will also enhance the responsiveness of light-sensitive parietal visual neurons (PVNs) in area PG of the

posterior parietal cortex 50 In experiments where monkeys are trained to fix their attention on a screen-and to keep on fixating even if no targets appearshythe excitability of these light-sensitive PVNs increases by as much as 350 51

52-53Responsiveness is also facilitated by the angle of gaze Also area PG is the first region in the visual pathways containing individual neurons with the capacity to respond to large bilateral stimuli moving in opposite directions along the central meridians of vision (opponent vector motion) 853-55 Facilitation of PVNs in area PG has the effect of sensitizing the subject to bilateral opponent vector motion and this is especially true if the movement appears in the periphery of the VE 8

Intracortical ampliftcation and feedback to the LGN When PGO waves and signals from the SC arrive in the primary visual cortex they may be relatively weak however weak signals can be amplified by reverberating in large networks

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 139

of cortical cells linked by local projection 56 There are nine times as many excitatory links among cortical cells as there are projections from the visual cortex to the LGN an imbalance which suggests leads Suarez Koch and Douglas to propose that geniculate input provides only a minor fraction of the excitatory input the majority originating in neighboring and recurrently connected cortical cells57 If the excitabiliry of cortical neurons is slightly higher than normal then this process of amplification may continue even after the LGN signals that initiated the reverberation are no longer being transmitted by the LGN ( a hysteretic mode of operation) 57

Feedback from hyperexcited cortical neurons will stream back to the LGN via corticogeniculate projections which outnumber geniculocortical projections ten-to-one One effect of this feedback is that the LGN is

able to absorb large amounts of information flowing back from the cortex 58

As signals reverberate back and forth in thalamocorticothalamic circuits a matching process takes place those geniculate relay cells that fire in patterns consistent with the firing patterns of active cortical cells will have their responshysivity enhanced while those geniculate cells that fire in patterns not consistent with cortical cells will be suppressed 59

Preservation of consciousness by selective facilitation of the visual pathways By combining all of the facilitatory effects produced by the authors eye movements and attentive fixation-(l) stimulation of the LGN by feedback from periorbital proprioception both directly and indirectly via the SC (2) the release of PGO waves (EMPs) that facilitate neurons in the LGN and primary visual cortex as they pass (3) the facilitation of the primary visual cortex by a state of relaxed immobile expectancy (4) attentive fixation and angle of gaze that facilitate PVNs in area PG (5) intracortical amplification of signals received from the LGN and (6) corticogeniculate feedback that stimulates the LGN-we delineate a circuit of enhanced excitability that extends from the LGN through the post-geniculate visual heirarchy to area PG where signals are integrated into representations of objects

The hyperexcitability of neurons all along the post-geniculate visual pathways creates conditions in the visual cortices which are similar to those present during EEG-desynchronized states of waking and REMS Therefore neurons in the visual pathways are too excitable to be entrained by synchronous bursting

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 140

patterns when spindle waves move through them instead the spindle bursts stimulate visual neurons to depolarize and then recover as happens in response to afferent sensory signals during waking states It is important to note that for this to occur none of the constituent neuron assemblies is required to perform an abnormal operation the abnormality is a function of the authors intent to activate contemporaneously neuron assemblies that would not normally be co-activated

PART IV HYPNOTIC ANALGESIA

Manipulation of spatial attention as a method for alleviating pain sensations In a theoretical article on the neurophysiology of hypnosis Crawford and Gruzelier60 propose that variations in hypnotizability are function of variability in the efficiency of the frontolimbic (anterior) attentional system in humans high-hypnotizables are better able to sustain focused attention on a task and to ignore extraneous stimuli than are low-hypnotizables

I na related empirical study that compares the use of attention by subjects with high versus low hypnotizability Crawford Brown and Moon61 report that highly hypnotizable persons continue to show physiological reactivity

while cognitively not perceiving the painful stimuli Through disattentional processes they can dissociate themselves from the awareness of pain The authors phosphene induction behaviors-and the cutaneous analgesia he experishyences-appear to involve the same kind of behaviors that is a mobilization of frontolimbic attention used to withdraw attention from external stimuli and to concentrate it on internally-generated phosphene images This suggests the hypothesis that the mechanisms that generate phosphenes might also produce hypnotic analgesia There are several ways that visual signals and pain signals might interact to produce this analgesia

Competition between pain and vision signals for limbic registration The fully-developed sensation of pain requires integration of rwo kinds of informashytion Signals that encode the location and intensity of a noxious stimulus (nociceptive signals) are relayed via the thalamus to the somatosensory cortices which registers only the sensory-discriminative aspects of pain perception62 before reaching consciousness the nociceptive signals must be sent to the limbic

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 141

system where they are linked with signals from long-term memory that encode the affective significance the stimulus has acquired for that individual Studies of brain metabolism show this linking of somatosensory information with limbic associations takes place in the anterior cingulate (CG) and anterior insula62-64

PET studies also show that the anterior CG is activated when subjects shift their spatial attention in response to expectations as to where

66stimuli will next appear65- This is precisely what takes place during the state of immobile expectancy that induces phosphenes Since visual signals and nociceptive signals both require limbic enhancement which is only possible if they get access to the anterior CG there might be conditions in which the two types of afferent sensory signals have to compete for that access In a theoretical article on the mechanisms of attention Posner and Rothbart67

propose that visual signals can interfere with nociceptive signals by blocking access to the anterior CG As behavioral evidence they cite studies showing that when young infants make distress calls they can be distracted by the presentation of a new visual stimulus We have shown the evidence of such control at about three months Orienting to visual events can be employed to quiet or calm negative vocalizations However the distress appears to be maintained and reappears when the infants attention to the stimulus is reduced Caregivers also report the use or visual orienting to block overt manifestations of distress at about this age 67

The effects of disattention on the somatosensory cortices If there is a competition between visual signals and nociceptive signals for access to the anterior CG it is likely that the competition will be affected by the relative volume of signals received A recent study suggests that focusing attention on internally-generated visual stimuli may reduce the number of nociceptive signals relayed by the somatosensory cortices Drevets Burton Videen Snyder Simpson and Raichle68 have shown that the mere anticipation of a touch at a specific cutaneous site increases the flow of blood to those cortical somatosenshysory neurons that are linked with that site where touch is expected and decreases the flow of blood to neurons linked with sites where touch is not expected In this experiment the researchers designated touch as the behaviorally significant sensory stimulus but their findings suggest that the outcome could be reversed if the instructions were reversed if subjects were

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page J42

instructed to direct attention away from a cutaneous site where a noxious stimulus was being applied if they were instructed to relax close their eyes and concentrate on the play of phosphenes in the visual field as the behaviorally significant sensory stimulus then it would be reasonable to expect that the flow of blood would decrease to the somatosensory neurons linked with the cutaneous stimulus and that the flow of blood would increase to the visual cortices The decrease in blood flow to somatosensory neurons implies less neuronal activity which implies that fewer signals are being sent forward to the anterior CG than would have been sent if instead the subject were treating the touch as the behaviorally significant sensory stimulus If fewer pain signals arrive at the anterior it is reasonable to infer that the conscious experience of pain will be muted by the diversion of attention to internal visual stimuli

Differential impact of sleep rhythms in the visual and nonvisual thalamus There is another mechanism that might also contribute to the analgesic effect of inducing sleep rhythms PET studies show that

the thalamus is involved in the relay of nociceptive signals to the cortex63 although some confusion remains about which kinds of signals are relayed by which subregions in the thalamus62 One thalamic site clearly identified by anatomical studies as a relay for nociceptive signals is the ventroposterior lateral nucleus (VPL)69 If synchronous sleep rhythms are active in the thalamus we can reasonably expect that the VPL will itself be entrained by synchronous oscillations and that it will relay the sleep rhythms to somatosensory cortices Relay neurons in the VPL are not stimulated by feedback from eye movements and fixation as are relay neurons in the LGN which suggests that sleep rhythms may impede the relay of nociceptive signals via the VPL but not the relay of visual signals via the LGN

Brain waves associated with anesthesia and NREMS The hypothesis presented here-that consciousness can be preserved despite the presence of NREMS activity-is consistent with a recent report that the kinds of fast brain waves which are normally associated with conscious states are also present during NREMS and anesthesia two states which were thought to involve minimal brain activityJo Another recent study found that there is a close resemblance between the slow brain waves that appear during NREMS and those that appear during certain types of anesthesia71

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 143

bull bull bull

CONCLUSION

In this paper we have presented evidence supporting the hypothesis that phosphene images can be generated as an epiphenomena of thalamic spindle bursts and delta wave activity normally associated with NREMS The prereqshyuisites for inducing these sleep rhythm phosphenes are relaxed immobile expectancy sustained convergence and attentive fixation of an undifferentiated visual field Our hypothesis provides a necessary and sufficient explanation for the authors induction of phosphenes and perhaps also for the generation of phosphenes reported to appear spontaneously during the drowsy transition to sleep (hypnagogic states) during sensory deprivation or during certain kinds of prayer or meditation all of which involve a similar state of relaxed immobile expectancyJ2

CORRESPONDENCE Philip T Nicholson bull 52 Norfolk Road bull Chestnut Hill MA 02167

REFERENCES amp NOTES

1 M 1 Posner Modulation by Instruction Nature 373 (1995) pp 198-199 2 J Reissenweber E David amp M pfotenhauer Investigations of Psychological Aspects of

the Perception of Magnetophosphenes and Electrophosphenes Biomedizinische Tecknik 373 (1992) pp 42-45

3 S M Kosslyn W L Thompson 1 J Kim amp N M Alpert Topographical Representations of Mental Images in Primary Visual Cortex Nature 378 (I995) pp 496-498

4 P E Roland amp B Gulyas Visual Memory Visual Imagery and Visual Recognition of Large Field Patterns by the Human Brain Functional Anatomy by Positron Emission Tomography Cerebral Cortex 51 (1995) pp 79-93

5 H Benson The Relaxation Response (Morrow New York NY 1975) 6 ] H Schultz amp W Luthe Autogenic Training a Physiological Approach to Psychotherapy

(Grune amp Stratton New York NY 1969) 7 E Jacobson Progressive Relaxation (University of Chicago Press Chicago IL 1938) 8 M A Steinmetz BC Motter C] DuffY amp V B Mountcastle Functional Properties

of Parietal Visual Neurons Radial Organization of Directionalities Within the Visual Field Journal ofNeuroscience 71 (1987) pp 177-191

9 R R Edelman Magnetic Resonance Imaging of the Nervous System Discussions in Neuroscience 71 Elsevier Science Amsterdam (I990) also J H Newhouse amp ] I Wiener Understanding MRI 1st Ed (Little Brown Boston MA 1991)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 144

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

so he had to begin the normal induction procedures after the dental work was already underway

A s the dentist worked on the first tooth the author experienced apprehension sharp sensations of pain and an involuntary tensing of the large muscles of the body with each application of the drill As

the author kept his eyes converged and his attention focused on the center of the visual field the involuntary tensing in response to pain alternated with a precipitous relaxing of those same muscles immediately after the stimulus With the repeated relaxation came a sense of relief and of letting go that amelioshyrated the pain The pain-driven relaxation was much stronger than the relaxation that normally accompanies the authors self-induction of phosphenes and the alternation of a pain-driven tensing on one hand and the distancing effect of focusing attention on the visual field on the other hand resulted in a rapid dissociation from all external and internal stimuli including a signifishycant amelioration of painful sensations

Most striking is the fact that by the time the dentist reached the third toothshyafter only a few minutes of this pain-driven self-hypnosis-the author saw a normal sequence of 4 receding annuli followed by swirling clouds of amorphous expanding phosphene even though the dentist was still using the drill contemporaneously This experience suggests that thalamic sleep rhythms can be voluntarily induced even when the subjects level of physiological arousal is high

SIMILARITIES WITH ATTENTION-INDUCED PHOSPHENES

REpORTED BY OTHER OBSERVERS

Taxonomies of phosphene images always include examples of simple geometric phosphenes with circular or semi-circular shapes (disks annuli or crescents) as

14well as formless phosphene mists 11 - There are also a number of anecdotal accounts that are relevant for example Friedman an opthamologist who studied entoptic images by introspection describes a similar sequence of annuli induced by sustained inward concentration Circular waves of blue color may be seen in the dark by the dark adapted retina They start at the

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 122

periphery and move inward toward the macula as a concentrically contracting solid circle disappear at the macula and begin again at the peripheryl)

A valuable but often-neglected resource of information about phosphene imagery is presented in the literature of religious mysticism Many mystics reported having seen translucent colored lights while absorbed in prayer or meditation A list of descriptions excerpted from self-reports is presented in Table 1 (These excerpts are representative of phosphene images that appear during states of calm and inward-oriented concentration they do not include images associated with paroxysmal raptures) These phosphene images exhibit a relatively limited set of shapes and colors the shapes are either circular (eg rings disks wheels suns) or formless (eg mists snow smoke) and the colors are usually a variant of either green or blue The phosphene visions of mystics display shapes and colors that are comparable to the images described by the author this and the many similarities in the behaviors used to induce phosphenes suggest that both sets of phosphenes have a common etiology

DISCUSSION

Whether the author uses self-hypnosis to induce phosphenes or experishyences them as hypnagogic images the threshold sequence of receding annuli has the same characteristics In both these

instances the antecedent behaviors involve a state of low physiological arousal combined with mental withdrawal from external stimuli These parallels suggest the hypothesis that phosphene displays are related to sleep-wake transitions

PART I RECEDING ANNULI AND THALAMIC SPINDLES

Mechanisms controlling the transition from waking to NREMS Based on the work of several research teams16-20 a consensus scenario for the generation of NREMS has emerged In this scenario NREMS is the product of three brain rhythms that interact with each other in thalamocorticothalamic circuits During the drowsy transition to sleep which in humans is called stage l NREMS the low voltage activity in the cortical electroencephalograph (EEG) still shows a pattern of intermittent desynchronization The polarization of

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 123

Table I Excerpts from self-reports of light visions by religious mystics

HEBREW MYSTICS the appearance of the wheels was like the gleaming of beryl and the four had the same form

their construction being something like a wheel within a wheel Ezekiel like a dome shining like crystal spread out about their heads And above the dome something

like a rhrone in appearance like sapphire Ezekiel a round Iodder like a full sphere rolling back and forth before him bright blue R Abulafia A glowing light clear brilliance A purple light that absorbs all lights R Moses de Leon

HINDU AND BUDDHIST MYSTICS a perfectly round beautiful deep-blue shape of a size appropriate to the center of a mandala as

if exquisitely painted of extreme c14rity Tsong Khapa a luminous revolving disc studded with lights a lotus flower in full bloom Gopi Krishna both my eyes became cemered When this happened a blue light arose in my eyes like

a candle flame without a wick and stood motionless in the ajna chakra S Muktananda

MUSLIM MYSTICS [like] chandelierssublime lights [like] stars moon or the sun Sharafuddin aI-Maneri its color is deep blue it seems to be an upsurge like water foom a spring Najmoddin Kobra visualize yourself as lying at the bottom of a well [looking up at the light of the opening] and

the well in lively downward movement Najmoddin Kobra the color green is the suprasensory uniting all the suprasensories Alaoddawleh Semnani the light rises in the Sky of the hean taking the form of light-gilling moons Najm Razi

CHRISTIAN MYSTICS his own state at prayer resembles a sapphire it is as clear and bright as the sky Evagrius descending like a bright cloud of mist like a sun round as a circle Simeon Neotheologos saw something in the air near him He did not understand the rype of thing but in some ways

it appeared to have the form of a serpent with many things that shone like eyes although they were not eyes Ignatius of Loyola

the soul puts on a green amilia [cape worn on shoulders beneath armor] John of the Cross [the almilla is like a helmet which] coverS all the senses of the head of the soul It has one

hole rhrough which the eyes may look upwards John of the Cross a round thing about rhe size of a rixdaier all bright and clear with light like a crystal H Hayen I saw a bright light and in this light the figure of a man the color of sapphireblazing with a

gentle glowing fire the three were in one light Hildegard von Bingen saw a b14zing fire incomprehensible inextinguishable with a flame in it the color of the sky

Hildegard von Bingen saw placed beneath her fuet the whole machine of the world as if it were a wheel She saw herself phced

above it her eyes of contemplation magnetized towards the incomprehensible Beatrice of Nazareth I saw the eyes I do not know if I was asleep or awake Angela of Foligno kind of sunlit winged being like a childs head beneath two little wings Abbess Thaisia laquobullbull round patterns small circles would expand and eventually dissipate only to be followed by other small

circles of light Philip St Romain an extraordinary circle of gold light pulsating against a deep violet background There were

always four or fille As soon as one would fode another would appear Philip St Romain

middotItalics added to mark words referring to (l) rings appearing in sets of four (2) amorphous shapes such as clouds or flames (3) circular or eye-like shapes (4) colors from the center of the visible spectrum (gold yellow yellow-green green bluish green) and (5) colors from the lower end of rhe visible spectrum (blue purple violet)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 124

cell membranes (Vm) has already begun to drop (hyperpolarize) in the thalamic reticular nucleus (RTN) a thin sheath of GABAnergic inhibitory neurons that acts as a pacemaker When the Vm of RTN cell membranes drops to approximately V m -60 millivolts (mV) RTN cells stop firing single spikes which are associated with waking states and instead begin firing highshyamplitude 7-14 Hertz (Hz) spike-bursts These bursts wax and wane over 1 to 3 seconds-hence the name spindle -and recur at 3 to 10 seconds Spindle volleys are relayed across the cortical mantle by thalamocortical (TC) sensory relay cells In human studies the primary criterion for onset of the first fullyshyestablished episode of NREMS or stage 2 sleep is the presence of globalized spindles in the cortical EEG

When spindle bursts from the RTN stimulate TC cells to fire in synchrony this synchronous bursting pattern overwhelms the normal capacity of TC cells to relay afferent sensory signals The loss of consciousness at the onset of stage 2 NREMS is thought to be caused by this blocking effect 21

While the RTN is firing spindle bursts through the thalamus another process is activated in the cortex large numbers of cells across the cortical mantle begin to oscillate at a very low frequency laquo 1 Hz)

The cortical slow rhythm referred back to the thalamus via corticothalamic circuits intensifies the hyperpolarizing effect of the RTN spindle bursts on TC cell membranes When V m -75 mV the TC cells begin to generate their own intrinsic calcium currents which further increases hyperpolarization At V m -90 mV the RTN neurons stop firing spindle bursts The TC cells continue to fire low-threshold calcium spikes in patterns which are controlled by the cortical slow rhythm The interaction of these two oscillations generates the delta waves (1 to 4 Hz) which are associated with stage 2 NREMS

In a study of sleep rhythms using the cortical EEG Uchida Atsumi and Kojima found that the mean number of spindles required to induce delta wave activity (that is to induce Vm = -90 mY) is 478 plusmn 162 spindles (from 3 to 7 spindles)22 The mean number of spindles in a volley remains the same for a single individual over multiple trials

Based on the consensus scenario for generation of NREMS we can predict that a phosphene image generated as an epiphenomenon of a thalamic spindle

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 125

Table II Dara show rhe degree of correspondance berween rhe pulse panerns of rhalamic spindles based on intracellular research and rhe sparioremporal panerns of receding annuli phosphenes induced by rhe author using a rechnique of self-hypnosis

Receding annuli phosphenes Thalamic spindle bursrs

Mean number of signals 4 annuli 487 (plusmn 16) bursrs

Sparial exrension vs Thin band 1 - 3 seconds durarion of signal ( 05 -15 cm)

Periodicity of signals 5 seconds 3 - 10 seconds

Simultaneity in LGNs Yes Yes

Point of entry Peripheral VF Ventral amp lareral LGN

Trajecrory Bilareral concentric Unknown

Rare of flow Cons rant rare Unknown

Signal-ro-noise rario High High (shorr bursrs) (sharp brighr discrere)

Termination of sequence Mrer 4 signals Mrer 487 (plusmn 16) signals

will present the following characteristics (1) a high-definition burst-like signal (2) that recurs within 3 to 10 seconds (3) that follows a trajectory compatible with having entered the LGN from the RTN (4) that has a predictable mean for the individual subject and a range that falls somewhere between 2 to 7 annuli and (5) that the spindles will terminate automatically

The temporal patterns of receding annuli and thalamic spindle bursts are similar Table II illustrates the close match between the timing of receding annuli phosphenes and thalamic spindle bursts The most striking similarities are the mean number of signals required to induce termination (4 annuli versus 487 spindles) and the interval between signals (5 seconds for annuli versus 3shyto-lO seconds for spindle bursts) Neither alpha theta nor beta waves present this kind of stereotyped temporal pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 126

T he spatial features of receding annuli are functions of geniculate anatomy A spindle burst moving through the LGN to the cortex will acquire certain distinctive spatiotemporal characteristics because of the

unique curvilinear and laminar anatomy of the LGN A drawing of a macaque LGN based on a clay model constructed by Le Gros Clark23 is shown in Figure 3 The primate LGN is composed of six sheets of cells or laminae that fold over a central hylus In macaques the hylus rises steeply as it extends rostrocausally forming a high arch at the posterior pole in humans the hylus is much more shallow but the functional anatomy is thought to be essentially

23 24the same in both cases - The geometry of the arch forces each lamina to bend so as to constitute in effect one-half of a conical surface and each lamina with its hemi-conical shape contains visual relay cells representing the contralatshyeral half of the visual field (VF) Operating as a pair the complementary hemishycones of the right and left LGN form the functional equivalent of a single conical surface which represents the entire VE This conical geometry of the paired LGNs means a burst of otherwise formless excitation will acquire a distinctive shape as it propagates through the laminae of the LGN Imagine a horizontal section moving along the surface of a cone from base to apex that moving section forms an annulus that shrinks in diameter as it approaches the apex but retains its annular symmetry throughout its trajectory

Figure 3 also includes drawings that show how Connolly and Van Essen24

converted the 3-dimensional structure of lamina 6 the largest and most dorsal layer into a 2-dimensional map Connolly and Van Essen used data obtained by Malpelli and Baker25 to superimpose a grid that specifies the areas in lamina 6 that contain TC cells representing various degrees of isoeccentricity in the VE We will use this map at a later point to show how the movement of a spindle wave through a pair of LGNs correlates with what appears in the VE

The location of the RTN relative to the LGN is also shown in Figure 3 The RTN spindle pacemaker is a thin sheath of GABAnergic inhibitory cells that extends along the surface of the whole posterior ventral thalamus not just the LGN This extension brings the RTN into close proximity with the portion of the LGN (lateral wing) that protrudes out from the main body of the thalamus Some of RTN wraps around and beneath the ventral edges of the LGN26 The RTN comes closest to the LGN in two areas along the ventral edges of the longest laminae (lamina 6 and 1) and along the edge of the lateral

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 127

DORSAL POLE DORSALPOIEA B

L1 L4 L3 L

DORSAL POlE DORSAL POIE (FOVEA)

G LATERAL WING

25

DORSAL POL (FOVEA)

10 _DIAL

20 WING

~

wing These areas contain TC cells that represent the far periphery of the VE If a spindle burst enters the LGN at locations where laminae are in closest proximity to the RTN-along the ventral edges-then the discharge of TC cells will begin in the most ventral portions of the laminae the regions that represent the far periphery of the VE This matches the phosphene sequence observed by the author

Our hypothesis about how this proximity between RTN and LGN affects the trajectory of spindle waves is illustrated in Figure 4 We propose that it is not possible for the author to observe a thin annulus of phosphene sweeping in from all 3600 of the peripheral VF unless spindle bursts exhibit the following

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 128

Figure 3 [facing page Drawings of primate geniculate anatomy and functional anatomy relevant to the generation ofphosphenes (A) Anterior view ofa macaque monkey LGN based on a clay model reconstruction by Le Gros Clark 23 (B) Posterior view ofthe same model showing 6 laminae folded over a central hylus to form lateral and medial wings with the hylus arching steeply upward near the posterior pole to shape the laminae into layers of hollow half-cones nested together Note that the lateral wing of the LGN is slightly larger than the medial wing so that in situ the lateral wing protrudes out from the main body of the thalamus creating a small knob visible during dissection 26 (C) Schematic drawing of an oblique section through median axis (also adapted from Le Gros Clark13 showing how the laminae fuse together at the anterior pole The afferent ganglion cell axons that form the optic tract (OT) penetrate through the anterior surface to reach their target relay cells in the laminae (D) Drawing of the most dorsal lamina-layer 6--separated from the rest of the LGN The geometric shape is a hollow half-cone so that right and left LGNs placed back-to-back form in effect a single cone Note also the position ofthe RTN shown here as a striped bar relative to lamina 6 The position of the striped bar shows that the RTN makes direct contact with lamina 6 at the edge ofthe lateral wing and also along the ventral edges (E - F) Schematic drawings adapted from Connolly and Van Essen24 that show how a 3-dimensional lamina-lamina 6--can be transformed into a 2-dimensional triangular figure lamina 6 is removed and its wings unfolded (E) creating a slightly asymmetric triangular figure (F) which is adjusted to an oblong shape (G) in order to superimshypose a grid matrix with minimal distortion The grid plots locations of TC cells that represent various isoelevations and isoazimuths in the VF locations derived from the experimental observations published by Malpeli and Baker 25 Note the relatively large amounts of laminar surface allocated to central vision (0 0

- 30 0) as compared

to peripheral vision (30 0 - 80 0)

characteristics (1) Spindle bursts must move simultaneously through both geniculate nuclei This pattern of movement is consistent with anatomical studies in primates that found axonal projections linking the right and left RTNs27-28 and with experimental studies in cats that found spindles appearing simultaneously in both right and left thalami 29 (2) Spindle waves must enter the ventral edges of the LGN first and move ventrodorsally in a highly coherent pattern-moving in effect as a standing wave This pattern of movement is consistent with in vitro experiments using sagittal slices from a ferret LGN where spindle waves originated spontaneously at the edge of a slice in an area which contains cells that represent peripheral vision then propagated toward that area of the slice containing cells that represent central vision in the ferret 3o

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 129

VF

PG BIlateral receptive lleJd of PVN YI(j Inward dmKooflality Adapled

0-- from Mortgr at at (1987)

V1

ibull t bull

RTN t t t t t t 1middot3 SECOlO BURSTS OF 7middot14 HZ SPiKES RECURRNG EVERY 3 10 SECONDS

To our knowledge the LGN is the only anatomical structure in the visual system that has the capacity of passively forcing a wave of excitation to flow across a conical surface thereby generating the sensation of a phosphene annulus that retains its symmetry as it shrinks in diameter The retina has a circular anatomy but it is not likely that the mechanical deformation of the retina would produce a wave that began simultaneously in all 3600 of the retinal rim nor that the symmetry of annular wave would be preserved as it flows inward toward the foveal region

The hypothesis presented here-that there is a structure in the visual system that imprints a conical shape on standing waves that move through it-explains

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 130

Figure 4 facing page Schematic drawing of contemporaneous events in selected regions of the visual processing hierarchy (A) The left and right RTNs fire spindle bursts simultaneously (B) The bursts pass through the right and left geniculate laminae as standing waves of depolarization entering from the ventral edges and moving ventrodorsally in parallel In order for the phosphene annulus to appear to be flowing at a constant rate the spindle wave flowing through the LCN must expand in width as it ascends ventrodorsally so that by the time the fill-in disk appears-when the center 30deg of the VF is covered by the phosphene annulus-the spindle wave must have expanded enough to activate relay cells in the most dorsal 50 of lamina 6 (C) Signals representing two complementary hemi-annuli are kept separate in the primary visual cortices (area VI) (D) Signals representing the two hemi-annuli are integrated into signals of a single annulus when they reach area PC in the posterior parietal cortex where the receptive fields of single parietal visual neurons have the capacity to register bilateral signals that exhibit opponent vector movement (that is signals converging from opposite directions along the central axes-as if an object were moving away from the viewer)46 Neurons in area PC also integrate wavelength (color) signals from the extrastriate visual pathway with signals about brightness motion and depth from the parietal visual pathway to compose a representation of an object in space-in this case of an annulus that appears to recede 32

the authors experience during MRI when he observed a continuous succession of receding annuli every 2 seconds in this view the energy of the electroshymagnetic bombardment when released during precessional relaxation flows through the geniculate laminae in the same way that the RTN spindle bursts do that is as a standing wave and thus the visual epiphenomenon is the same in both cases if the subject keeps the eyes focused straight ahead and the attention fixated In a study of phosphenes evoked by electricity in conjunction with hallucinogenic drugs Knoll Kugler Hofer and Lawder found that each subject sees specific kinds of phosphene at different frequencies and that these frequency-specific images are stable enough to be reproduced after six months31

They conclude that the tunability of the electrical stimulation frequenshycies within the EEG range to various definable phosphenes requires the existence of a resonance system One mechanism contributing to that resonance system may be the functional anatomy of the LGN

The colors of receding annuli as functions of geniculate laminar anatomy The colors of receding annuli phosphenes are consistent with the patterns of discharge spindle waves can be expected to stimulate as they move through

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 131

geniculate laminae As shown in Figure 5 the six laminae differ (1) in the types of wavelength signals relayed (2) in physical size and (3) in the area of the VF represented 24-25 Only 4 out of 6 laminae Cparvocellular layers 3shy6) contain TC cells that relay wavelength signals the other 2 laminae (magnocellular layers 1 and 2) do not encode wavelength Among parvocelshylular laminae only lamina 6 the longest and most dorsal layer contains TC cells that can represent the far periphery of the VF (from 800 to 50deg of isoeccenshytdeity) therefore when the spindle wave enters the peripheral VF only those wavelengths relayed by lamina 6 will participate in composing a cortical lightness record (See Zeki)32

I n lamina 6 ganglion cell axons arriving from the retina carry two kinds of wavelength signals (1) center-ON signals from medium-wavelength cones (M-cone center-ON) and long-wavelength cones (L-cone centershy

ON)33-35 Using the cone spectral sensitivity curves (adapted from Marks et al 36) we average the wavelengths that elicit maximal responses for M-cones (535 nanometers) and L-cones (520 nm) which yields a mean wavelength value of 550 nm In humans this wavelength generates a sensation of green or yellowshygreen the sensation observed by the author

As the spindle burst moves ventrodorsally it reaches the dorsal areas in the geniculate laminae which contain TC cells representing the central 0deg to 20deg of isoeccentrieity in the VE All 4 parvocellular laminae have TC cells which are potentially capable of representing this central region of vision but the authors observation that the color of the filling-in disk changed from green to blue implies that in the early years of phosphene induction the spindle wave must have remained close to the surface of the LGN stimulating only laminae 5 and 6 which generates a sensation of yellow-green When the fill-in disk was observed to change color from green to blue the spindle wave must have been rechanneled so that it began to penetrate below laminae 5 and 6 and to activate laminae 3 and 4 the only laminae that relay blue-sensitive signals (Sshycone center-ON signals)3 In light of the authors MRI experience it seems likely that a spindle wave requires a minimum of 2 seconds to reach the blueshysensitive cells of laminae 4 therefore during MRI when the receding annuli disappeared after 2 seconds half the normal duration the fill-disk had a green color even though it had long since change to blue in other induction settings with a 4-second trajectory

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 132

A REPRESENTATION OF THE VISUAL FIELD IN EACH LAMINA

orooqUtftc O-u OCIJ1SALfIOLI (I01flAj

0

10

20

30

40 n50 Of

60

70

20 loO 1Mgr_ II~ o UIpoundAS65 mn1MY-o actlvncL ~~~r

Jll-COMcetlImiddot~

II LAYERSU 3 GatQYancetl~ (1) ucon ceom-oyenF (2)l~cen()FF 3) ~ cenloH

II~ cng1loqctWIIIfNla

iICINe -- (t81Otdb1t1d~OH (2)~

80

B CONE SPECTRAL SENSITIVITY CURVES

S-COHS

WAVIlLllNG1llS OF UGHT IH NANOMllTERS (NM)

Figure 5 Phosphene color as a function of ganglion cell distribution in parvocellular laminae (Aj Schematic drawing ofthe proportion ofthe VF represented in each laminae The proportions shown here are based on the work of Connolly and Van Essen24 The

far periphery of vision (50 0 to 80 0 of isoeccentricity) is represented in only two laminae-laminae 1 and 6-and of these two only lamina 6 is a parvocelLular lamina capable ofencoding wavelength signals Therefore only those wavelengths relayed by lamina 6 will participate in forming a cortical lighmess record for the far periphery of the VP (B) Cone spectral sensitivity curves (adapted from Marks et al)36 Using these cone sensitivity curves we can estimate the sensation stimulated by a spindle wave moving through lamina 6 by averaging the wavelengths that elicit maximal responses for M-cones (535 nanomeshyters) and L-cones (520 nm) which yields a mean wavelength value of550 nm In humans this generates a sensation of green or yellow-green the sensation observed by the author when the receding annulus enters at the far periphery of the VP For a calculation of the cortical lightness record when a spindle wave moves through 20deg to 0deg ofthe VF stimulating all 4 parvocelfular laminae see the text and Figure 6

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 133

Once the spindle wave penetrates to laminae 3 and 4 it may activate all 4 parvocellular laminae stimulating TC cells to send contradictory wavelength signals for the same retinotopic location the signals sent from laminae 4 and 3 will encode blue light (S-cone center-ON plus M-cone center-OFF and Lshycone center-OFF) while the signals sent from laminae 5 and 6 encode yellowshygreen light (M-cone center-ON plus L-cone center-ON) This kind of contrashydiction does not occur in normal retina-based perception where light energy striking the retina is structured by the retinas center-surround and colorshyopponent organization to encode only one set of wavelength signals for each spatial locus 32 In Figure 6 we estimate the cortical lightness record that results when contradictory wavelength signals compete to be represented in consciousshyness Our calculations suggest that the outcome will be a mean wavelength which in humans elicits a dark blue or violet sensation

PART II AMORPHOUS PHOSPHENES amp THALAMIC DELTA ACTMTY

M echanisms controlling the transition from spindle bursts to delta activity In the consensus scenario for the generation of NREMS16-20 we noted that the RTN shifts to firing spindle bursts

when polarization of thalamic cell membranes drops to V m = - 60 mV At the same time cortical cells begin oscillating with a synchronous slow rhythm laquo 1 Hz) Both processes further decrease the Vm of TC cell membranes When Vm = - 75 mY TC cells begin to generate their own intrinsic calcium currents which also decreases V m At V m = - 90 mV RTN neurons stop firing spindle bursts At the same time the TC cells begin firing low-threshold calcium spikes in alternation with after-hyperpolarizations (LTS-AHP) Because sensory relay neurons in the LGN are not linked to one another by locally projecting axons the firing of one TC cell does not excite its neighbor However a lack of local connectivity does not mean that TC cells occupying the same laminae release their AHP-LTS calcium spikes in a random distribshyution rather spikes are released simultaneously by groups of cells in synchrony with the advent of the cortical slow wave In effect the distribution of LTSshyAHP spikes firing in the LGN is determined by the spatial propagation of the cortical slow wave Thus the delta wave (1 to 4 Hz) activity detected by cortical EEG during NREMS is a product of the interaction between the AHP-LTS calcium spikes released by TC cells and the cortical slow rhythm

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 134

CORTICAL PROCESSING OF CONTRADICTORY

WAVELENGTH SIGNALS

KEY _ Cells firing

cJ Cononol firing

Assume that as a spind6e wave moves through the LGNlt fires simultaneously aU the TC cells that represent a particular reUnoshytopic locus (x y) in each of the six laminae As a result cortical cells engaged In the higher level processing of visual signals will receive more wavelength signals representing retina locus (x y) than are generated by normal perception laquo and some of these afferent wavelength signals may contradict other signals arriving simultaneously

CORTICAL LIGHTNESS RECORD SlgnalSell

Intemal contradictions not congruent wilt pre

SmiddotON eristing neuron neta

s bullbull M-ON LmiddotON

3 bullbull M-OFF + L-OFF

a-ON 12

ROD-ON

No Internal eonlradlemiddot

--------1I =~8b~~~~~~~t signals

3+4

~ --OFF Excludes 6 Of 7 $J9n18

1+2 B-ON I

IWmiddotHmiddotI Signal Sell

1111111 No Intern1 conlrfldlcshy lion

Exelvdta 4 out of 7 efshy

bullbullbull bullbullbull ferant signals

No Intern1 contradic_ tionnee S-ON BshyOH and ROO-ON can all be coacllve at low lImlnance levels nef Ihe rod-eone break

ExchJde$ only 2 Ollt of 7 afferent signals

Figure 6 Selection of competing wavelength signals based on neuronal group selection This thought experiment is based on Edelman sconcept ofneuronal group selection 73 We assume that all possible combinations ofsignals will form sets and that all signal-sets will compete to make the most efficient match with pre-existing neuromd networks that have been forged over years ofnorma reti1U1-based perception We also assume that pre-existing neural networks are most likely to expedite those sets that satisfY 2 criteriI (J) the signals in a set do not contradict each other and (2) fower signals are excluded than in the other sets that satisfY the first criterion In our analysis Set 4 wins the competition because it does not contain internal contradictions and excludes fower signals (2 out of 7) than Set 3 excludes (4 out of7) It is not an internal contradiction that Set 4 contains both rods and cone Signtlls in normal retina-based perception when luminance levels approach the rod-cone break S-cone center-ON receptors send signas as do rod receptors and there is even evidence that rod activity may actually drive S-cone activity even after luminance levels foIl below the rod-cone break74 To calculate the cortical lightness record for Set 4 we average the wavelength that elicits maximal responses foom rods (511 nm) and for Sshycones (430 nm) which yields a mean wavelength of 470 nm which in humans results in a dark-blue or violet sensation

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 135

The cortical slow rhythm is an example of a generic pattern of neuronal excitashytion that occurs in large networks of neurons linked by local projections A recent experiment by Maeda Robinson and Kwana38 shows that networks of locally-connected neurons spontaneously generate periodic synchronized bursts of calcium transients that propagate across the network in an expanding spatial wave a pattern that represents a stable mode of firing towards which these neuronal networks relax following perturbations for example by electronic stimulation or by drugs Understanding the characteristics of these waves is an important prerequisite to understanding the mechanisms that produce the amorphous phosphene images as a visual epiphenomenon

To study the spontaneous periodic synchronized bursts the researchers prepared cultures of dissociated cortical neurons and allowed them to mature for several days in vitro (DIV) After 3 to 4 DIV when concenshy

trations of extracellular magnesium were low electrodes began to detect spontaneous synchronized bursts of low frequency calcium transients (between 01 and 1 Hz) that originated in different locations on the sheet every 10 to 20 seconds and spread across the sheet of cells at a relatively slow speed averaging 50 mmsecond The researchers could not predict where a wave would originate or where it would expand rather the initiation and expansion of waves was generated by spatial and temporal summation of a continuous random background of synaptic inputs including miniature spontaneous synaptic events but the pattern was not random since waves propagated sequentially from electrode to electrode as each local group of neurons charges up its neighboring nontefractory areas rather than in a random sequence of regions38

The excitability of the cells in the sheet determines the probability first that there will be a synchronous burst and second that it will spread in a particshyular direction Cells become more excitable as the cultures mature which means the refractory intervals between successive bursts were much shorter in mature cultures (gt 30 DIV) than in early cultures laquo 7 DIV) Some cells became so insensitive to inhibition that they continued to fire bursts even when extracellular concentrations of magnesium were relatively high Finally there were refractory periods of 5 to 10 seconds during which no bursts occurred even when an electrical stimulus was applied This refractory interval for cultured networks is slightly longer than the refractory interval observed of the cortical slow wave in vivo which 25 to 4 seconds 18- 19

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 136

Based on the observations about cortical slow waves we can predict that phosphenes generated as epiphenomena of delta wave activity will present the following signal characteristics (1) signals that appear at unpredictable locations in the VF (2) signals that expand and diverge asymmetrically following unpredictable trajectories which may encompass large areas of the VF (3) signals that move relatively slowly (50 mmsec) (4) signals that recur with a period of 2 to 4 seconds reflecting entrainment by the cortical slow wave (5) signals that do not terminate automatically after a predictable number of cycles

The spatial patterns of phosphene mists and thalamic delta waves are similar The spatiotemporal characteristics of amorphous phosphenes match the pattern of wave propagation associated with periodic spontashy

neous synchronized bursts in large neuron networks the amorphous phosphenes enter the visual field at unpredictable locations expand and diverge asymmetrically with a slow steady rate of flow follow trajectories that are unpredictable and exhibit a refractory interval The amorphous mists do appear to have a periodicity although the author is unable to sustain the vision while also counting the seconds therefore he is unable to determine if it compares to the period of the cortical slow wave (25 to 4 seconds) but his impression is that it feels roughly the same as as with receding annuli which recur at 5 seconds Also the refractory interval feels as if it decreases as the induction session is extended These similarities suggest that the amorphous phosphenes are generated by stage 2 NREMS delta wave activity which is an activity governed by the reverberation of the cortical slow wave in thalamoshycorticothalamic circuits The cortical slow wave is referred to the LGN where it modulates the firing of visual relay cells in the laminae and since relay cells do not have local dendritic connections the expansion of a wave of depolarshyizations moving from one relay cell to the next across in the laminar surface will mirror at least in part the expansion of the cortical wave that is spreading contemporaneously through locally-connected cortical cells

PART III RETENTION OF CONSCIOUSNESS

In a normal transition to NREMS the volley of synchronous spindle bursts that marks the onset of stage 2 NREMS overwhelms the normal firing pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 137

of thalamocortical cells preventing their relay of afferent sensory signals and inducing a loss of consciousness21 But the loss of consciousness cannot be timed precisely using cortical EEG the thalamus is too remote for the onset of spindling to be reliably detected by scalp electrodes39 In experiments with cats where electrodes could be implanted in the thalamus researchers found that spindling often reached peak levels of activity in the thalamus-a level of activity consonant with stage 2 NREMS-at a time when the cortical EEG was still showing intermittent desynchronizations a pattern characteristic of the drowsy stage 1 transition not a fully-established stage 2 NREMS episode4o

In other words there is a short period of time in which the synchronous rhythms of stage 2 NREMS are installed in the thalamus but not in the cortex where cortical neurons continue to depolarize in response to afferent sensory signals

T his finding suggests a possible explanation for the authors ability to retain consciousness while spindle bursts are sweeping through the LGN if he is able to extend the duration of this time lag between

the onset of spindling in the thalamus and spindling in the cortex if he is able to stimulate the visual cortices in such a way that they continue to depolarize then he may be able to keep on processing visual signals-to remain visually aware-even after the non-visual thalamus and non-visual cortex become entrained by synchronous sleep rhythms The authors induction technique includes several behaviors which are known to enhance the responsiveness of visual neurons-eye movements attentive fixation and an attitude of expectancy

Effects of eye movements and attention on the LGN Sustained convergence causes periorbital proprioceptors to send excitatory feedback directly to the LGN41 Also convergence further enhances the excitability of geniculate cells by stimulating the superior collicus (SC) which sends its own excitatory signals to the LGN42-43 These signals from the SC are known to selectively enhance the excitability of visual relay cells that represent the periphery of vision44 We know in the authors case that the SC is being stimulated because he is able to keep on fixating an ability which would normally be lost during the transishytion to NREMS45 The ability to fixate can be retained however if the SC is stimulated (even if stimulated during NREMS)46

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 138

Effects of eye movement attention and expectancy on the primary visual cortex The PET study of mental imagery by Kosslyn et al 3 showed that even a baseline resting state of relaxed immobile expectancy can generate signifishycant increases in neuronal activity in the primary visual cortices Further increases can be induced by sustained eye movements

A sustained convergence will release a stream of ponto-geniculo-occipital (PGO) waves These PGO waves called eye movement potentials or EMPs last only as long as the eye movement1747 whereas the PGO waves associated with rapid-eye-movement sleep (REMS) fire continually for the duration of the REMS episode Both REMS-related PGO waves and EMPs have the same desynchronizing effect on the visual pathways they move through the LGN depolarizing the thalamocortical cells which relay the signals to cortical neurons The responsivity of neurons in the primary visual cortices is enhanced by the stimulation of PGO waves 1747-49 If the passage of EMPs causes the genicushylate relay cells and their cortical targets to depolarize regularly then a volley of 4 spindle bursts moving through the same pathways will register as just another series of depolarizations in effect the spindle bursts are processed by the visual system as if they were sensory signals sent from the retina rather than an event stimulated by endogenous mechanisms

T he impact of eye movements and ftxation on the parietal visual cortex Convergence and attentive fixation will also enhance the responsiveness of light-sensitive parietal visual neurons (PVNs) in area PG of the

posterior parietal cortex 50 In experiments where monkeys are trained to fix their attention on a screen-and to keep on fixating even if no targets appearshythe excitability of these light-sensitive PVNs increases by as much as 350 51

52-53Responsiveness is also facilitated by the angle of gaze Also area PG is the first region in the visual pathways containing individual neurons with the capacity to respond to large bilateral stimuli moving in opposite directions along the central meridians of vision (opponent vector motion) 853-55 Facilitation of PVNs in area PG has the effect of sensitizing the subject to bilateral opponent vector motion and this is especially true if the movement appears in the periphery of the VE 8

Intracortical ampliftcation and feedback to the LGN When PGO waves and signals from the SC arrive in the primary visual cortex they may be relatively weak however weak signals can be amplified by reverberating in large networks

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 139

of cortical cells linked by local projection 56 There are nine times as many excitatory links among cortical cells as there are projections from the visual cortex to the LGN an imbalance which suggests leads Suarez Koch and Douglas to propose that geniculate input provides only a minor fraction of the excitatory input the majority originating in neighboring and recurrently connected cortical cells57 If the excitabiliry of cortical neurons is slightly higher than normal then this process of amplification may continue even after the LGN signals that initiated the reverberation are no longer being transmitted by the LGN ( a hysteretic mode of operation) 57

Feedback from hyperexcited cortical neurons will stream back to the LGN via corticogeniculate projections which outnumber geniculocortical projections ten-to-one One effect of this feedback is that the LGN is

able to absorb large amounts of information flowing back from the cortex 58

As signals reverberate back and forth in thalamocorticothalamic circuits a matching process takes place those geniculate relay cells that fire in patterns consistent with the firing patterns of active cortical cells will have their responshysivity enhanced while those geniculate cells that fire in patterns not consistent with cortical cells will be suppressed 59

Preservation of consciousness by selective facilitation of the visual pathways By combining all of the facilitatory effects produced by the authors eye movements and attentive fixation-(l) stimulation of the LGN by feedback from periorbital proprioception both directly and indirectly via the SC (2) the release of PGO waves (EMPs) that facilitate neurons in the LGN and primary visual cortex as they pass (3) the facilitation of the primary visual cortex by a state of relaxed immobile expectancy (4) attentive fixation and angle of gaze that facilitate PVNs in area PG (5) intracortical amplification of signals received from the LGN and (6) corticogeniculate feedback that stimulates the LGN-we delineate a circuit of enhanced excitability that extends from the LGN through the post-geniculate visual heirarchy to area PG where signals are integrated into representations of objects

The hyperexcitability of neurons all along the post-geniculate visual pathways creates conditions in the visual cortices which are similar to those present during EEG-desynchronized states of waking and REMS Therefore neurons in the visual pathways are too excitable to be entrained by synchronous bursting

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 140

patterns when spindle waves move through them instead the spindle bursts stimulate visual neurons to depolarize and then recover as happens in response to afferent sensory signals during waking states It is important to note that for this to occur none of the constituent neuron assemblies is required to perform an abnormal operation the abnormality is a function of the authors intent to activate contemporaneously neuron assemblies that would not normally be co-activated

PART IV HYPNOTIC ANALGESIA

Manipulation of spatial attention as a method for alleviating pain sensations In a theoretical article on the neurophysiology of hypnosis Crawford and Gruzelier60 propose that variations in hypnotizability are function of variability in the efficiency of the frontolimbic (anterior) attentional system in humans high-hypnotizables are better able to sustain focused attention on a task and to ignore extraneous stimuli than are low-hypnotizables

I na related empirical study that compares the use of attention by subjects with high versus low hypnotizability Crawford Brown and Moon61 report that highly hypnotizable persons continue to show physiological reactivity

while cognitively not perceiving the painful stimuli Through disattentional processes they can dissociate themselves from the awareness of pain The authors phosphene induction behaviors-and the cutaneous analgesia he experishyences-appear to involve the same kind of behaviors that is a mobilization of frontolimbic attention used to withdraw attention from external stimuli and to concentrate it on internally-generated phosphene images This suggests the hypothesis that the mechanisms that generate phosphenes might also produce hypnotic analgesia There are several ways that visual signals and pain signals might interact to produce this analgesia

Competition between pain and vision signals for limbic registration The fully-developed sensation of pain requires integration of rwo kinds of informashytion Signals that encode the location and intensity of a noxious stimulus (nociceptive signals) are relayed via the thalamus to the somatosensory cortices which registers only the sensory-discriminative aspects of pain perception62 before reaching consciousness the nociceptive signals must be sent to the limbic

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 141

system where they are linked with signals from long-term memory that encode the affective significance the stimulus has acquired for that individual Studies of brain metabolism show this linking of somatosensory information with limbic associations takes place in the anterior cingulate (CG) and anterior insula62-64

PET studies also show that the anterior CG is activated when subjects shift their spatial attention in response to expectations as to where

66stimuli will next appear65- This is precisely what takes place during the state of immobile expectancy that induces phosphenes Since visual signals and nociceptive signals both require limbic enhancement which is only possible if they get access to the anterior CG there might be conditions in which the two types of afferent sensory signals have to compete for that access In a theoretical article on the mechanisms of attention Posner and Rothbart67

propose that visual signals can interfere with nociceptive signals by blocking access to the anterior CG As behavioral evidence they cite studies showing that when young infants make distress calls they can be distracted by the presentation of a new visual stimulus We have shown the evidence of such control at about three months Orienting to visual events can be employed to quiet or calm negative vocalizations However the distress appears to be maintained and reappears when the infants attention to the stimulus is reduced Caregivers also report the use or visual orienting to block overt manifestations of distress at about this age 67

The effects of disattention on the somatosensory cortices If there is a competition between visual signals and nociceptive signals for access to the anterior CG it is likely that the competition will be affected by the relative volume of signals received A recent study suggests that focusing attention on internally-generated visual stimuli may reduce the number of nociceptive signals relayed by the somatosensory cortices Drevets Burton Videen Snyder Simpson and Raichle68 have shown that the mere anticipation of a touch at a specific cutaneous site increases the flow of blood to those cortical somatosenshysory neurons that are linked with that site where touch is expected and decreases the flow of blood to neurons linked with sites where touch is not expected In this experiment the researchers designated touch as the behaviorally significant sensory stimulus but their findings suggest that the outcome could be reversed if the instructions were reversed if subjects were

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page J42

instructed to direct attention away from a cutaneous site where a noxious stimulus was being applied if they were instructed to relax close their eyes and concentrate on the play of phosphenes in the visual field as the behaviorally significant sensory stimulus then it would be reasonable to expect that the flow of blood would decrease to the somatosensory neurons linked with the cutaneous stimulus and that the flow of blood would increase to the visual cortices The decrease in blood flow to somatosensory neurons implies less neuronal activity which implies that fewer signals are being sent forward to the anterior CG than would have been sent if instead the subject were treating the touch as the behaviorally significant sensory stimulus If fewer pain signals arrive at the anterior it is reasonable to infer that the conscious experience of pain will be muted by the diversion of attention to internal visual stimuli

Differential impact of sleep rhythms in the visual and nonvisual thalamus There is another mechanism that might also contribute to the analgesic effect of inducing sleep rhythms PET studies show that

the thalamus is involved in the relay of nociceptive signals to the cortex63 although some confusion remains about which kinds of signals are relayed by which subregions in the thalamus62 One thalamic site clearly identified by anatomical studies as a relay for nociceptive signals is the ventroposterior lateral nucleus (VPL)69 If synchronous sleep rhythms are active in the thalamus we can reasonably expect that the VPL will itself be entrained by synchronous oscillations and that it will relay the sleep rhythms to somatosensory cortices Relay neurons in the VPL are not stimulated by feedback from eye movements and fixation as are relay neurons in the LGN which suggests that sleep rhythms may impede the relay of nociceptive signals via the VPL but not the relay of visual signals via the LGN

Brain waves associated with anesthesia and NREMS The hypothesis presented here-that consciousness can be preserved despite the presence of NREMS activity-is consistent with a recent report that the kinds of fast brain waves which are normally associated with conscious states are also present during NREMS and anesthesia two states which were thought to involve minimal brain activityJo Another recent study found that there is a close resemblance between the slow brain waves that appear during NREMS and those that appear during certain types of anesthesia71

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 143

bull bull bull

CONCLUSION

In this paper we have presented evidence supporting the hypothesis that phosphene images can be generated as an epiphenomena of thalamic spindle bursts and delta wave activity normally associated with NREMS The prereqshyuisites for inducing these sleep rhythm phosphenes are relaxed immobile expectancy sustained convergence and attentive fixation of an undifferentiated visual field Our hypothesis provides a necessary and sufficient explanation for the authors induction of phosphenes and perhaps also for the generation of phosphenes reported to appear spontaneously during the drowsy transition to sleep (hypnagogic states) during sensory deprivation or during certain kinds of prayer or meditation all of which involve a similar state of relaxed immobile expectancyJ2

CORRESPONDENCE Philip T Nicholson bull 52 Norfolk Road bull Chestnut Hill MA 02167

REFERENCES amp NOTES

1 M 1 Posner Modulation by Instruction Nature 373 (1995) pp 198-199 2 J Reissenweber E David amp M pfotenhauer Investigations of Psychological Aspects of

the Perception of Magnetophosphenes and Electrophosphenes Biomedizinische Tecknik 373 (1992) pp 42-45

3 S M Kosslyn W L Thompson 1 J Kim amp N M Alpert Topographical Representations of Mental Images in Primary Visual Cortex Nature 378 (I995) pp 496-498

4 P E Roland amp B Gulyas Visual Memory Visual Imagery and Visual Recognition of Large Field Patterns by the Human Brain Functional Anatomy by Positron Emission Tomography Cerebral Cortex 51 (1995) pp 79-93

5 H Benson The Relaxation Response (Morrow New York NY 1975) 6 ] H Schultz amp W Luthe Autogenic Training a Physiological Approach to Psychotherapy

(Grune amp Stratton New York NY 1969) 7 E Jacobson Progressive Relaxation (University of Chicago Press Chicago IL 1938) 8 M A Steinmetz BC Motter C] DuffY amp V B Mountcastle Functional Properties

of Parietal Visual Neurons Radial Organization of Directionalities Within the Visual Field Journal ofNeuroscience 71 (1987) pp 177-191

9 R R Edelman Magnetic Resonance Imaging of the Nervous System Discussions in Neuroscience 71 Elsevier Science Amsterdam (I990) also J H Newhouse amp ] I Wiener Understanding MRI 1st Ed (Little Brown Boston MA 1991)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 144

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

periphery and move inward toward the macula as a concentrically contracting solid circle disappear at the macula and begin again at the peripheryl)

A valuable but often-neglected resource of information about phosphene imagery is presented in the literature of religious mysticism Many mystics reported having seen translucent colored lights while absorbed in prayer or meditation A list of descriptions excerpted from self-reports is presented in Table 1 (These excerpts are representative of phosphene images that appear during states of calm and inward-oriented concentration they do not include images associated with paroxysmal raptures) These phosphene images exhibit a relatively limited set of shapes and colors the shapes are either circular (eg rings disks wheels suns) or formless (eg mists snow smoke) and the colors are usually a variant of either green or blue The phosphene visions of mystics display shapes and colors that are comparable to the images described by the author this and the many similarities in the behaviors used to induce phosphenes suggest that both sets of phosphenes have a common etiology

DISCUSSION

Whether the author uses self-hypnosis to induce phosphenes or experishyences them as hypnagogic images the threshold sequence of receding annuli has the same characteristics In both these

instances the antecedent behaviors involve a state of low physiological arousal combined with mental withdrawal from external stimuli These parallels suggest the hypothesis that phosphene displays are related to sleep-wake transitions

PART I RECEDING ANNULI AND THALAMIC SPINDLES

Mechanisms controlling the transition from waking to NREMS Based on the work of several research teams16-20 a consensus scenario for the generation of NREMS has emerged In this scenario NREMS is the product of three brain rhythms that interact with each other in thalamocorticothalamic circuits During the drowsy transition to sleep which in humans is called stage l NREMS the low voltage activity in the cortical electroencephalograph (EEG) still shows a pattern of intermittent desynchronization The polarization of

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 123

Table I Excerpts from self-reports of light visions by religious mystics

HEBREW MYSTICS the appearance of the wheels was like the gleaming of beryl and the four had the same form

their construction being something like a wheel within a wheel Ezekiel like a dome shining like crystal spread out about their heads And above the dome something

like a rhrone in appearance like sapphire Ezekiel a round Iodder like a full sphere rolling back and forth before him bright blue R Abulafia A glowing light clear brilliance A purple light that absorbs all lights R Moses de Leon

HINDU AND BUDDHIST MYSTICS a perfectly round beautiful deep-blue shape of a size appropriate to the center of a mandala as

if exquisitely painted of extreme c14rity Tsong Khapa a luminous revolving disc studded with lights a lotus flower in full bloom Gopi Krishna both my eyes became cemered When this happened a blue light arose in my eyes like

a candle flame without a wick and stood motionless in the ajna chakra S Muktananda

MUSLIM MYSTICS [like] chandelierssublime lights [like] stars moon or the sun Sharafuddin aI-Maneri its color is deep blue it seems to be an upsurge like water foom a spring Najmoddin Kobra visualize yourself as lying at the bottom of a well [looking up at the light of the opening] and

the well in lively downward movement Najmoddin Kobra the color green is the suprasensory uniting all the suprasensories Alaoddawleh Semnani the light rises in the Sky of the hean taking the form of light-gilling moons Najm Razi

CHRISTIAN MYSTICS his own state at prayer resembles a sapphire it is as clear and bright as the sky Evagrius descending like a bright cloud of mist like a sun round as a circle Simeon Neotheologos saw something in the air near him He did not understand the rype of thing but in some ways

it appeared to have the form of a serpent with many things that shone like eyes although they were not eyes Ignatius of Loyola

the soul puts on a green amilia [cape worn on shoulders beneath armor] John of the Cross [the almilla is like a helmet which] coverS all the senses of the head of the soul It has one

hole rhrough which the eyes may look upwards John of the Cross a round thing about rhe size of a rixdaier all bright and clear with light like a crystal H Hayen I saw a bright light and in this light the figure of a man the color of sapphireblazing with a

gentle glowing fire the three were in one light Hildegard von Bingen saw a b14zing fire incomprehensible inextinguishable with a flame in it the color of the sky

Hildegard von Bingen saw placed beneath her fuet the whole machine of the world as if it were a wheel She saw herself phced

above it her eyes of contemplation magnetized towards the incomprehensible Beatrice of Nazareth I saw the eyes I do not know if I was asleep or awake Angela of Foligno kind of sunlit winged being like a childs head beneath two little wings Abbess Thaisia laquobullbull round patterns small circles would expand and eventually dissipate only to be followed by other small

circles of light Philip St Romain an extraordinary circle of gold light pulsating against a deep violet background There were

always four or fille As soon as one would fode another would appear Philip St Romain

middotItalics added to mark words referring to (l) rings appearing in sets of four (2) amorphous shapes such as clouds or flames (3) circular or eye-like shapes (4) colors from the center of the visible spectrum (gold yellow yellow-green green bluish green) and (5) colors from the lower end of rhe visible spectrum (blue purple violet)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 124

cell membranes (Vm) has already begun to drop (hyperpolarize) in the thalamic reticular nucleus (RTN) a thin sheath of GABAnergic inhibitory neurons that acts as a pacemaker When the Vm of RTN cell membranes drops to approximately V m -60 millivolts (mV) RTN cells stop firing single spikes which are associated with waking states and instead begin firing highshyamplitude 7-14 Hertz (Hz) spike-bursts These bursts wax and wane over 1 to 3 seconds-hence the name spindle -and recur at 3 to 10 seconds Spindle volleys are relayed across the cortical mantle by thalamocortical (TC) sensory relay cells In human studies the primary criterion for onset of the first fullyshyestablished episode of NREMS or stage 2 sleep is the presence of globalized spindles in the cortical EEG

When spindle bursts from the RTN stimulate TC cells to fire in synchrony this synchronous bursting pattern overwhelms the normal capacity of TC cells to relay afferent sensory signals The loss of consciousness at the onset of stage 2 NREMS is thought to be caused by this blocking effect 21

While the RTN is firing spindle bursts through the thalamus another process is activated in the cortex large numbers of cells across the cortical mantle begin to oscillate at a very low frequency laquo 1 Hz)

The cortical slow rhythm referred back to the thalamus via corticothalamic circuits intensifies the hyperpolarizing effect of the RTN spindle bursts on TC cell membranes When V m -75 mV the TC cells begin to generate their own intrinsic calcium currents which further increases hyperpolarization At V m -90 mV the RTN neurons stop firing spindle bursts The TC cells continue to fire low-threshold calcium spikes in patterns which are controlled by the cortical slow rhythm The interaction of these two oscillations generates the delta waves (1 to 4 Hz) which are associated with stage 2 NREMS

In a study of sleep rhythms using the cortical EEG Uchida Atsumi and Kojima found that the mean number of spindles required to induce delta wave activity (that is to induce Vm = -90 mY) is 478 plusmn 162 spindles (from 3 to 7 spindles)22 The mean number of spindles in a volley remains the same for a single individual over multiple trials

Based on the consensus scenario for generation of NREMS we can predict that a phosphene image generated as an epiphenomenon of a thalamic spindle

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 125

Table II Dara show rhe degree of correspondance berween rhe pulse panerns of rhalamic spindles based on intracellular research and rhe sparioremporal panerns of receding annuli phosphenes induced by rhe author using a rechnique of self-hypnosis

Receding annuli phosphenes Thalamic spindle bursrs

Mean number of signals 4 annuli 487 (plusmn 16) bursrs

Sparial exrension vs Thin band 1 - 3 seconds durarion of signal ( 05 -15 cm)

Periodicity of signals 5 seconds 3 - 10 seconds

Simultaneity in LGNs Yes Yes

Point of entry Peripheral VF Ventral amp lareral LGN

Trajecrory Bilareral concentric Unknown

Rare of flow Cons rant rare Unknown

Signal-ro-noise rario High High (shorr bursrs) (sharp brighr discrere)

Termination of sequence Mrer 4 signals Mrer 487 (plusmn 16) signals

will present the following characteristics (1) a high-definition burst-like signal (2) that recurs within 3 to 10 seconds (3) that follows a trajectory compatible with having entered the LGN from the RTN (4) that has a predictable mean for the individual subject and a range that falls somewhere between 2 to 7 annuli and (5) that the spindles will terminate automatically

The temporal patterns of receding annuli and thalamic spindle bursts are similar Table II illustrates the close match between the timing of receding annuli phosphenes and thalamic spindle bursts The most striking similarities are the mean number of signals required to induce termination (4 annuli versus 487 spindles) and the interval between signals (5 seconds for annuli versus 3shyto-lO seconds for spindle bursts) Neither alpha theta nor beta waves present this kind of stereotyped temporal pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 126

T he spatial features of receding annuli are functions of geniculate anatomy A spindle burst moving through the LGN to the cortex will acquire certain distinctive spatiotemporal characteristics because of the

unique curvilinear and laminar anatomy of the LGN A drawing of a macaque LGN based on a clay model constructed by Le Gros Clark23 is shown in Figure 3 The primate LGN is composed of six sheets of cells or laminae that fold over a central hylus In macaques the hylus rises steeply as it extends rostrocausally forming a high arch at the posterior pole in humans the hylus is much more shallow but the functional anatomy is thought to be essentially

23 24the same in both cases - The geometry of the arch forces each lamina to bend so as to constitute in effect one-half of a conical surface and each lamina with its hemi-conical shape contains visual relay cells representing the contralatshyeral half of the visual field (VF) Operating as a pair the complementary hemishycones of the right and left LGN form the functional equivalent of a single conical surface which represents the entire VE This conical geometry of the paired LGNs means a burst of otherwise formless excitation will acquire a distinctive shape as it propagates through the laminae of the LGN Imagine a horizontal section moving along the surface of a cone from base to apex that moving section forms an annulus that shrinks in diameter as it approaches the apex but retains its annular symmetry throughout its trajectory

Figure 3 also includes drawings that show how Connolly and Van Essen24

converted the 3-dimensional structure of lamina 6 the largest and most dorsal layer into a 2-dimensional map Connolly and Van Essen used data obtained by Malpelli and Baker25 to superimpose a grid that specifies the areas in lamina 6 that contain TC cells representing various degrees of isoeccentricity in the VE We will use this map at a later point to show how the movement of a spindle wave through a pair of LGNs correlates with what appears in the VE

The location of the RTN relative to the LGN is also shown in Figure 3 The RTN spindle pacemaker is a thin sheath of GABAnergic inhibitory cells that extends along the surface of the whole posterior ventral thalamus not just the LGN This extension brings the RTN into close proximity with the portion of the LGN (lateral wing) that protrudes out from the main body of the thalamus Some of RTN wraps around and beneath the ventral edges of the LGN26 The RTN comes closest to the LGN in two areas along the ventral edges of the longest laminae (lamina 6 and 1) and along the edge of the lateral

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 127

DORSAL POLE DORSALPOIEA B

L1 L4 L3 L

DORSAL POlE DORSAL POIE (FOVEA)

G LATERAL WING

25

DORSAL POL (FOVEA)

10 _DIAL

20 WING

~

wing These areas contain TC cells that represent the far periphery of the VE If a spindle burst enters the LGN at locations where laminae are in closest proximity to the RTN-along the ventral edges-then the discharge of TC cells will begin in the most ventral portions of the laminae the regions that represent the far periphery of the VE This matches the phosphene sequence observed by the author

Our hypothesis about how this proximity between RTN and LGN affects the trajectory of spindle waves is illustrated in Figure 4 We propose that it is not possible for the author to observe a thin annulus of phosphene sweeping in from all 3600 of the peripheral VF unless spindle bursts exhibit the following

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 128

Figure 3 [facing page Drawings of primate geniculate anatomy and functional anatomy relevant to the generation ofphosphenes (A) Anterior view ofa macaque monkey LGN based on a clay model reconstruction by Le Gros Clark 23 (B) Posterior view ofthe same model showing 6 laminae folded over a central hylus to form lateral and medial wings with the hylus arching steeply upward near the posterior pole to shape the laminae into layers of hollow half-cones nested together Note that the lateral wing of the LGN is slightly larger than the medial wing so that in situ the lateral wing protrudes out from the main body of the thalamus creating a small knob visible during dissection 26 (C) Schematic drawing of an oblique section through median axis (also adapted from Le Gros Clark13 showing how the laminae fuse together at the anterior pole The afferent ganglion cell axons that form the optic tract (OT) penetrate through the anterior surface to reach their target relay cells in the laminae (D) Drawing of the most dorsal lamina-layer 6--separated from the rest of the LGN The geometric shape is a hollow half-cone so that right and left LGNs placed back-to-back form in effect a single cone Note also the position ofthe RTN shown here as a striped bar relative to lamina 6 The position of the striped bar shows that the RTN makes direct contact with lamina 6 at the edge ofthe lateral wing and also along the ventral edges (E - F) Schematic drawings adapted from Connolly and Van Essen24 that show how a 3-dimensional lamina-lamina 6--can be transformed into a 2-dimensional triangular figure lamina 6 is removed and its wings unfolded (E) creating a slightly asymmetric triangular figure (F) which is adjusted to an oblong shape (G) in order to superimshypose a grid matrix with minimal distortion The grid plots locations of TC cells that represent various isoelevations and isoazimuths in the VF locations derived from the experimental observations published by Malpeli and Baker 25 Note the relatively large amounts of laminar surface allocated to central vision (0 0

- 30 0) as compared

to peripheral vision (30 0 - 80 0)

characteristics (1) Spindle bursts must move simultaneously through both geniculate nuclei This pattern of movement is consistent with anatomical studies in primates that found axonal projections linking the right and left RTNs27-28 and with experimental studies in cats that found spindles appearing simultaneously in both right and left thalami 29 (2) Spindle waves must enter the ventral edges of the LGN first and move ventrodorsally in a highly coherent pattern-moving in effect as a standing wave This pattern of movement is consistent with in vitro experiments using sagittal slices from a ferret LGN where spindle waves originated spontaneously at the edge of a slice in an area which contains cells that represent peripheral vision then propagated toward that area of the slice containing cells that represent central vision in the ferret 3o

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 129

VF

PG BIlateral receptive lleJd of PVN YI(j Inward dmKooflality Adapled

0-- from Mortgr at at (1987)

V1

ibull t bull

RTN t t t t t t 1middot3 SECOlO BURSTS OF 7middot14 HZ SPiKES RECURRNG EVERY 3 10 SECONDS

To our knowledge the LGN is the only anatomical structure in the visual system that has the capacity of passively forcing a wave of excitation to flow across a conical surface thereby generating the sensation of a phosphene annulus that retains its symmetry as it shrinks in diameter The retina has a circular anatomy but it is not likely that the mechanical deformation of the retina would produce a wave that began simultaneously in all 3600 of the retinal rim nor that the symmetry of annular wave would be preserved as it flows inward toward the foveal region

The hypothesis presented here-that there is a structure in the visual system that imprints a conical shape on standing waves that move through it-explains

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 130

Figure 4 facing page Schematic drawing of contemporaneous events in selected regions of the visual processing hierarchy (A) The left and right RTNs fire spindle bursts simultaneously (B) The bursts pass through the right and left geniculate laminae as standing waves of depolarization entering from the ventral edges and moving ventrodorsally in parallel In order for the phosphene annulus to appear to be flowing at a constant rate the spindle wave flowing through the LCN must expand in width as it ascends ventrodorsally so that by the time the fill-in disk appears-when the center 30deg of the VF is covered by the phosphene annulus-the spindle wave must have expanded enough to activate relay cells in the most dorsal 50 of lamina 6 (C) Signals representing two complementary hemi-annuli are kept separate in the primary visual cortices (area VI) (D) Signals representing the two hemi-annuli are integrated into signals of a single annulus when they reach area PC in the posterior parietal cortex where the receptive fields of single parietal visual neurons have the capacity to register bilateral signals that exhibit opponent vector movement (that is signals converging from opposite directions along the central axes-as if an object were moving away from the viewer)46 Neurons in area PC also integrate wavelength (color) signals from the extrastriate visual pathway with signals about brightness motion and depth from the parietal visual pathway to compose a representation of an object in space-in this case of an annulus that appears to recede 32

the authors experience during MRI when he observed a continuous succession of receding annuli every 2 seconds in this view the energy of the electroshymagnetic bombardment when released during precessional relaxation flows through the geniculate laminae in the same way that the RTN spindle bursts do that is as a standing wave and thus the visual epiphenomenon is the same in both cases if the subject keeps the eyes focused straight ahead and the attention fixated In a study of phosphenes evoked by electricity in conjunction with hallucinogenic drugs Knoll Kugler Hofer and Lawder found that each subject sees specific kinds of phosphene at different frequencies and that these frequency-specific images are stable enough to be reproduced after six months31

They conclude that the tunability of the electrical stimulation frequenshycies within the EEG range to various definable phosphenes requires the existence of a resonance system One mechanism contributing to that resonance system may be the functional anatomy of the LGN

The colors of receding annuli as functions of geniculate laminar anatomy The colors of receding annuli phosphenes are consistent with the patterns of discharge spindle waves can be expected to stimulate as they move through

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 131

geniculate laminae As shown in Figure 5 the six laminae differ (1) in the types of wavelength signals relayed (2) in physical size and (3) in the area of the VF represented 24-25 Only 4 out of 6 laminae Cparvocellular layers 3shy6) contain TC cells that relay wavelength signals the other 2 laminae (magnocellular layers 1 and 2) do not encode wavelength Among parvocelshylular laminae only lamina 6 the longest and most dorsal layer contains TC cells that can represent the far periphery of the VF (from 800 to 50deg of isoeccenshytdeity) therefore when the spindle wave enters the peripheral VF only those wavelengths relayed by lamina 6 will participate in composing a cortical lightness record (See Zeki)32

I n lamina 6 ganglion cell axons arriving from the retina carry two kinds of wavelength signals (1) center-ON signals from medium-wavelength cones (M-cone center-ON) and long-wavelength cones (L-cone centershy

ON)33-35 Using the cone spectral sensitivity curves (adapted from Marks et al 36) we average the wavelengths that elicit maximal responses for M-cones (535 nanometers) and L-cones (520 nm) which yields a mean wavelength value of 550 nm In humans this wavelength generates a sensation of green or yellowshygreen the sensation observed by the author

As the spindle burst moves ventrodorsally it reaches the dorsal areas in the geniculate laminae which contain TC cells representing the central 0deg to 20deg of isoeccentrieity in the VE All 4 parvocellular laminae have TC cells which are potentially capable of representing this central region of vision but the authors observation that the color of the filling-in disk changed from green to blue implies that in the early years of phosphene induction the spindle wave must have remained close to the surface of the LGN stimulating only laminae 5 and 6 which generates a sensation of yellow-green When the fill-in disk was observed to change color from green to blue the spindle wave must have been rechanneled so that it began to penetrate below laminae 5 and 6 and to activate laminae 3 and 4 the only laminae that relay blue-sensitive signals (Sshycone center-ON signals)3 In light of the authors MRI experience it seems likely that a spindle wave requires a minimum of 2 seconds to reach the blueshysensitive cells of laminae 4 therefore during MRI when the receding annuli disappeared after 2 seconds half the normal duration the fill-disk had a green color even though it had long since change to blue in other induction settings with a 4-second trajectory

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 132

A REPRESENTATION OF THE VISUAL FIELD IN EACH LAMINA

orooqUtftc O-u OCIJ1SALfIOLI (I01flAj

0

10

20

30

40 n50 Of

60

70

20 loO 1Mgr_ II~ o UIpoundAS65 mn1MY-o actlvncL ~~~r

Jll-COMcetlImiddot~

II LAYERSU 3 GatQYancetl~ (1) ucon ceom-oyenF (2)l~cen()FF 3) ~ cenloH

II~ cng1loqctWIIIfNla

iICINe -- (t81Otdb1t1d~OH (2)~

80

B CONE SPECTRAL SENSITIVITY CURVES

S-COHS

WAVIlLllNG1llS OF UGHT IH NANOMllTERS (NM)

Figure 5 Phosphene color as a function of ganglion cell distribution in parvocellular laminae (Aj Schematic drawing ofthe proportion ofthe VF represented in each laminae The proportions shown here are based on the work of Connolly and Van Essen24 The

far periphery of vision (50 0 to 80 0 of isoeccentricity) is represented in only two laminae-laminae 1 and 6-and of these two only lamina 6 is a parvocelLular lamina capable ofencoding wavelength signals Therefore only those wavelengths relayed by lamina 6 will participate in forming a cortical lighmess record for the far periphery of the VP (B) Cone spectral sensitivity curves (adapted from Marks et al)36 Using these cone sensitivity curves we can estimate the sensation stimulated by a spindle wave moving through lamina 6 by averaging the wavelengths that elicit maximal responses for M-cones (535 nanomeshyters) and L-cones (520 nm) which yields a mean wavelength value of550 nm In humans this generates a sensation of green or yellow-green the sensation observed by the author when the receding annulus enters at the far periphery of the VP For a calculation of the cortical lightness record when a spindle wave moves through 20deg to 0deg ofthe VF stimulating all 4 parvocelfular laminae see the text and Figure 6

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 133

Once the spindle wave penetrates to laminae 3 and 4 it may activate all 4 parvocellular laminae stimulating TC cells to send contradictory wavelength signals for the same retinotopic location the signals sent from laminae 4 and 3 will encode blue light (S-cone center-ON plus M-cone center-OFF and Lshycone center-OFF) while the signals sent from laminae 5 and 6 encode yellowshygreen light (M-cone center-ON plus L-cone center-ON) This kind of contrashydiction does not occur in normal retina-based perception where light energy striking the retina is structured by the retinas center-surround and colorshyopponent organization to encode only one set of wavelength signals for each spatial locus 32 In Figure 6 we estimate the cortical lightness record that results when contradictory wavelength signals compete to be represented in consciousshyness Our calculations suggest that the outcome will be a mean wavelength which in humans elicits a dark blue or violet sensation

PART II AMORPHOUS PHOSPHENES amp THALAMIC DELTA ACTMTY

M echanisms controlling the transition from spindle bursts to delta activity In the consensus scenario for the generation of NREMS16-20 we noted that the RTN shifts to firing spindle bursts

when polarization of thalamic cell membranes drops to V m = - 60 mV At the same time cortical cells begin oscillating with a synchronous slow rhythm laquo 1 Hz) Both processes further decrease the Vm of TC cell membranes When Vm = - 75 mY TC cells begin to generate their own intrinsic calcium currents which also decreases V m At V m = - 90 mV RTN neurons stop firing spindle bursts At the same time the TC cells begin firing low-threshold calcium spikes in alternation with after-hyperpolarizations (LTS-AHP) Because sensory relay neurons in the LGN are not linked to one another by locally projecting axons the firing of one TC cell does not excite its neighbor However a lack of local connectivity does not mean that TC cells occupying the same laminae release their AHP-LTS calcium spikes in a random distribshyution rather spikes are released simultaneously by groups of cells in synchrony with the advent of the cortical slow wave In effect the distribution of LTSshyAHP spikes firing in the LGN is determined by the spatial propagation of the cortical slow wave Thus the delta wave (1 to 4 Hz) activity detected by cortical EEG during NREMS is a product of the interaction between the AHP-LTS calcium spikes released by TC cells and the cortical slow rhythm

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 134

CORTICAL PROCESSING OF CONTRADICTORY

WAVELENGTH SIGNALS

KEY _ Cells firing

cJ Cononol firing

Assume that as a spind6e wave moves through the LGNlt fires simultaneously aU the TC cells that represent a particular reUnoshytopic locus (x y) in each of the six laminae As a result cortical cells engaged In the higher level processing of visual signals will receive more wavelength signals representing retina locus (x y) than are generated by normal perception laquo and some of these afferent wavelength signals may contradict other signals arriving simultaneously

CORTICAL LIGHTNESS RECORD SlgnalSell

Intemal contradictions not congruent wilt pre

SmiddotON eristing neuron neta

s bullbull M-ON LmiddotON

3 bullbull M-OFF + L-OFF

a-ON 12

ROD-ON

No Internal eonlradlemiddot

--------1I =~8b~~~~~~~t signals

3+4

~ --OFF Excludes 6 Of 7 $J9n18

1+2 B-ON I

IWmiddotHmiddotI Signal Sell

1111111 No Intern1 conlrfldlcshy lion

Exelvdta 4 out of 7 efshy

bullbullbull bullbullbull ferant signals

No Intern1 contradic_ tionnee S-ON BshyOH and ROO-ON can all be coacllve at low lImlnance levels nef Ihe rod-eone break

ExchJde$ only 2 Ollt of 7 afferent signals

Figure 6 Selection of competing wavelength signals based on neuronal group selection This thought experiment is based on Edelman sconcept ofneuronal group selection 73 We assume that all possible combinations ofsignals will form sets and that all signal-sets will compete to make the most efficient match with pre-existing neuromd networks that have been forged over years ofnorma reti1U1-based perception We also assume that pre-existing neural networks are most likely to expedite those sets that satisfY 2 criteriI (J) the signals in a set do not contradict each other and (2) fower signals are excluded than in the other sets that satisfY the first criterion In our analysis Set 4 wins the competition because it does not contain internal contradictions and excludes fower signals (2 out of 7) than Set 3 excludes (4 out of7) It is not an internal contradiction that Set 4 contains both rods and cone Signtlls in normal retina-based perception when luminance levels approach the rod-cone break S-cone center-ON receptors send signas as do rod receptors and there is even evidence that rod activity may actually drive S-cone activity even after luminance levels foIl below the rod-cone break74 To calculate the cortical lightness record for Set 4 we average the wavelength that elicits maximal responses foom rods (511 nm) and for Sshycones (430 nm) which yields a mean wavelength of 470 nm which in humans results in a dark-blue or violet sensation

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 135

The cortical slow rhythm is an example of a generic pattern of neuronal excitashytion that occurs in large networks of neurons linked by local projections A recent experiment by Maeda Robinson and Kwana38 shows that networks of locally-connected neurons spontaneously generate periodic synchronized bursts of calcium transients that propagate across the network in an expanding spatial wave a pattern that represents a stable mode of firing towards which these neuronal networks relax following perturbations for example by electronic stimulation or by drugs Understanding the characteristics of these waves is an important prerequisite to understanding the mechanisms that produce the amorphous phosphene images as a visual epiphenomenon

To study the spontaneous periodic synchronized bursts the researchers prepared cultures of dissociated cortical neurons and allowed them to mature for several days in vitro (DIV) After 3 to 4 DIV when concenshy

trations of extracellular magnesium were low electrodes began to detect spontaneous synchronized bursts of low frequency calcium transients (between 01 and 1 Hz) that originated in different locations on the sheet every 10 to 20 seconds and spread across the sheet of cells at a relatively slow speed averaging 50 mmsecond The researchers could not predict where a wave would originate or where it would expand rather the initiation and expansion of waves was generated by spatial and temporal summation of a continuous random background of synaptic inputs including miniature spontaneous synaptic events but the pattern was not random since waves propagated sequentially from electrode to electrode as each local group of neurons charges up its neighboring nontefractory areas rather than in a random sequence of regions38

The excitability of the cells in the sheet determines the probability first that there will be a synchronous burst and second that it will spread in a particshyular direction Cells become more excitable as the cultures mature which means the refractory intervals between successive bursts were much shorter in mature cultures (gt 30 DIV) than in early cultures laquo 7 DIV) Some cells became so insensitive to inhibition that they continued to fire bursts even when extracellular concentrations of magnesium were relatively high Finally there were refractory periods of 5 to 10 seconds during which no bursts occurred even when an electrical stimulus was applied This refractory interval for cultured networks is slightly longer than the refractory interval observed of the cortical slow wave in vivo which 25 to 4 seconds 18- 19

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 136

Based on the observations about cortical slow waves we can predict that phosphenes generated as epiphenomena of delta wave activity will present the following signal characteristics (1) signals that appear at unpredictable locations in the VF (2) signals that expand and diverge asymmetrically following unpredictable trajectories which may encompass large areas of the VF (3) signals that move relatively slowly (50 mmsec) (4) signals that recur with a period of 2 to 4 seconds reflecting entrainment by the cortical slow wave (5) signals that do not terminate automatically after a predictable number of cycles

The spatial patterns of phosphene mists and thalamic delta waves are similar The spatiotemporal characteristics of amorphous phosphenes match the pattern of wave propagation associated with periodic spontashy

neous synchronized bursts in large neuron networks the amorphous phosphenes enter the visual field at unpredictable locations expand and diverge asymmetrically with a slow steady rate of flow follow trajectories that are unpredictable and exhibit a refractory interval The amorphous mists do appear to have a periodicity although the author is unable to sustain the vision while also counting the seconds therefore he is unable to determine if it compares to the period of the cortical slow wave (25 to 4 seconds) but his impression is that it feels roughly the same as as with receding annuli which recur at 5 seconds Also the refractory interval feels as if it decreases as the induction session is extended These similarities suggest that the amorphous phosphenes are generated by stage 2 NREMS delta wave activity which is an activity governed by the reverberation of the cortical slow wave in thalamoshycorticothalamic circuits The cortical slow wave is referred to the LGN where it modulates the firing of visual relay cells in the laminae and since relay cells do not have local dendritic connections the expansion of a wave of depolarshyizations moving from one relay cell to the next across in the laminar surface will mirror at least in part the expansion of the cortical wave that is spreading contemporaneously through locally-connected cortical cells

PART III RETENTION OF CONSCIOUSNESS

In a normal transition to NREMS the volley of synchronous spindle bursts that marks the onset of stage 2 NREMS overwhelms the normal firing pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 137

of thalamocortical cells preventing their relay of afferent sensory signals and inducing a loss of consciousness21 But the loss of consciousness cannot be timed precisely using cortical EEG the thalamus is too remote for the onset of spindling to be reliably detected by scalp electrodes39 In experiments with cats where electrodes could be implanted in the thalamus researchers found that spindling often reached peak levels of activity in the thalamus-a level of activity consonant with stage 2 NREMS-at a time when the cortical EEG was still showing intermittent desynchronizations a pattern characteristic of the drowsy stage 1 transition not a fully-established stage 2 NREMS episode4o

In other words there is a short period of time in which the synchronous rhythms of stage 2 NREMS are installed in the thalamus but not in the cortex where cortical neurons continue to depolarize in response to afferent sensory signals

T his finding suggests a possible explanation for the authors ability to retain consciousness while spindle bursts are sweeping through the LGN if he is able to extend the duration of this time lag between

the onset of spindling in the thalamus and spindling in the cortex if he is able to stimulate the visual cortices in such a way that they continue to depolarize then he may be able to keep on processing visual signals-to remain visually aware-even after the non-visual thalamus and non-visual cortex become entrained by synchronous sleep rhythms The authors induction technique includes several behaviors which are known to enhance the responsiveness of visual neurons-eye movements attentive fixation and an attitude of expectancy

Effects of eye movements and attention on the LGN Sustained convergence causes periorbital proprioceptors to send excitatory feedback directly to the LGN41 Also convergence further enhances the excitability of geniculate cells by stimulating the superior collicus (SC) which sends its own excitatory signals to the LGN42-43 These signals from the SC are known to selectively enhance the excitability of visual relay cells that represent the periphery of vision44 We know in the authors case that the SC is being stimulated because he is able to keep on fixating an ability which would normally be lost during the transishytion to NREMS45 The ability to fixate can be retained however if the SC is stimulated (even if stimulated during NREMS)46

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 138

Effects of eye movement attention and expectancy on the primary visual cortex The PET study of mental imagery by Kosslyn et al 3 showed that even a baseline resting state of relaxed immobile expectancy can generate signifishycant increases in neuronal activity in the primary visual cortices Further increases can be induced by sustained eye movements

A sustained convergence will release a stream of ponto-geniculo-occipital (PGO) waves These PGO waves called eye movement potentials or EMPs last only as long as the eye movement1747 whereas the PGO waves associated with rapid-eye-movement sleep (REMS) fire continually for the duration of the REMS episode Both REMS-related PGO waves and EMPs have the same desynchronizing effect on the visual pathways they move through the LGN depolarizing the thalamocortical cells which relay the signals to cortical neurons The responsivity of neurons in the primary visual cortices is enhanced by the stimulation of PGO waves 1747-49 If the passage of EMPs causes the genicushylate relay cells and their cortical targets to depolarize regularly then a volley of 4 spindle bursts moving through the same pathways will register as just another series of depolarizations in effect the spindle bursts are processed by the visual system as if they were sensory signals sent from the retina rather than an event stimulated by endogenous mechanisms

T he impact of eye movements and ftxation on the parietal visual cortex Convergence and attentive fixation will also enhance the responsiveness of light-sensitive parietal visual neurons (PVNs) in area PG of the

posterior parietal cortex 50 In experiments where monkeys are trained to fix their attention on a screen-and to keep on fixating even if no targets appearshythe excitability of these light-sensitive PVNs increases by as much as 350 51

52-53Responsiveness is also facilitated by the angle of gaze Also area PG is the first region in the visual pathways containing individual neurons with the capacity to respond to large bilateral stimuli moving in opposite directions along the central meridians of vision (opponent vector motion) 853-55 Facilitation of PVNs in area PG has the effect of sensitizing the subject to bilateral opponent vector motion and this is especially true if the movement appears in the periphery of the VE 8

Intracortical ampliftcation and feedback to the LGN When PGO waves and signals from the SC arrive in the primary visual cortex they may be relatively weak however weak signals can be amplified by reverberating in large networks

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 139

of cortical cells linked by local projection 56 There are nine times as many excitatory links among cortical cells as there are projections from the visual cortex to the LGN an imbalance which suggests leads Suarez Koch and Douglas to propose that geniculate input provides only a minor fraction of the excitatory input the majority originating in neighboring and recurrently connected cortical cells57 If the excitabiliry of cortical neurons is slightly higher than normal then this process of amplification may continue even after the LGN signals that initiated the reverberation are no longer being transmitted by the LGN ( a hysteretic mode of operation) 57

Feedback from hyperexcited cortical neurons will stream back to the LGN via corticogeniculate projections which outnumber geniculocortical projections ten-to-one One effect of this feedback is that the LGN is

able to absorb large amounts of information flowing back from the cortex 58

As signals reverberate back and forth in thalamocorticothalamic circuits a matching process takes place those geniculate relay cells that fire in patterns consistent with the firing patterns of active cortical cells will have their responshysivity enhanced while those geniculate cells that fire in patterns not consistent with cortical cells will be suppressed 59

Preservation of consciousness by selective facilitation of the visual pathways By combining all of the facilitatory effects produced by the authors eye movements and attentive fixation-(l) stimulation of the LGN by feedback from periorbital proprioception both directly and indirectly via the SC (2) the release of PGO waves (EMPs) that facilitate neurons in the LGN and primary visual cortex as they pass (3) the facilitation of the primary visual cortex by a state of relaxed immobile expectancy (4) attentive fixation and angle of gaze that facilitate PVNs in area PG (5) intracortical amplification of signals received from the LGN and (6) corticogeniculate feedback that stimulates the LGN-we delineate a circuit of enhanced excitability that extends from the LGN through the post-geniculate visual heirarchy to area PG where signals are integrated into representations of objects

The hyperexcitability of neurons all along the post-geniculate visual pathways creates conditions in the visual cortices which are similar to those present during EEG-desynchronized states of waking and REMS Therefore neurons in the visual pathways are too excitable to be entrained by synchronous bursting

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 140

patterns when spindle waves move through them instead the spindle bursts stimulate visual neurons to depolarize and then recover as happens in response to afferent sensory signals during waking states It is important to note that for this to occur none of the constituent neuron assemblies is required to perform an abnormal operation the abnormality is a function of the authors intent to activate contemporaneously neuron assemblies that would not normally be co-activated

PART IV HYPNOTIC ANALGESIA

Manipulation of spatial attention as a method for alleviating pain sensations In a theoretical article on the neurophysiology of hypnosis Crawford and Gruzelier60 propose that variations in hypnotizability are function of variability in the efficiency of the frontolimbic (anterior) attentional system in humans high-hypnotizables are better able to sustain focused attention on a task and to ignore extraneous stimuli than are low-hypnotizables

I na related empirical study that compares the use of attention by subjects with high versus low hypnotizability Crawford Brown and Moon61 report that highly hypnotizable persons continue to show physiological reactivity

while cognitively not perceiving the painful stimuli Through disattentional processes they can dissociate themselves from the awareness of pain The authors phosphene induction behaviors-and the cutaneous analgesia he experishyences-appear to involve the same kind of behaviors that is a mobilization of frontolimbic attention used to withdraw attention from external stimuli and to concentrate it on internally-generated phosphene images This suggests the hypothesis that the mechanisms that generate phosphenes might also produce hypnotic analgesia There are several ways that visual signals and pain signals might interact to produce this analgesia

Competition between pain and vision signals for limbic registration The fully-developed sensation of pain requires integration of rwo kinds of informashytion Signals that encode the location and intensity of a noxious stimulus (nociceptive signals) are relayed via the thalamus to the somatosensory cortices which registers only the sensory-discriminative aspects of pain perception62 before reaching consciousness the nociceptive signals must be sent to the limbic

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 141

system where they are linked with signals from long-term memory that encode the affective significance the stimulus has acquired for that individual Studies of brain metabolism show this linking of somatosensory information with limbic associations takes place in the anterior cingulate (CG) and anterior insula62-64

PET studies also show that the anterior CG is activated when subjects shift their spatial attention in response to expectations as to where

66stimuli will next appear65- This is precisely what takes place during the state of immobile expectancy that induces phosphenes Since visual signals and nociceptive signals both require limbic enhancement which is only possible if they get access to the anterior CG there might be conditions in which the two types of afferent sensory signals have to compete for that access In a theoretical article on the mechanisms of attention Posner and Rothbart67

propose that visual signals can interfere with nociceptive signals by blocking access to the anterior CG As behavioral evidence they cite studies showing that when young infants make distress calls they can be distracted by the presentation of a new visual stimulus We have shown the evidence of such control at about three months Orienting to visual events can be employed to quiet or calm negative vocalizations However the distress appears to be maintained and reappears when the infants attention to the stimulus is reduced Caregivers also report the use or visual orienting to block overt manifestations of distress at about this age 67

The effects of disattention on the somatosensory cortices If there is a competition between visual signals and nociceptive signals for access to the anterior CG it is likely that the competition will be affected by the relative volume of signals received A recent study suggests that focusing attention on internally-generated visual stimuli may reduce the number of nociceptive signals relayed by the somatosensory cortices Drevets Burton Videen Snyder Simpson and Raichle68 have shown that the mere anticipation of a touch at a specific cutaneous site increases the flow of blood to those cortical somatosenshysory neurons that are linked with that site where touch is expected and decreases the flow of blood to neurons linked with sites where touch is not expected In this experiment the researchers designated touch as the behaviorally significant sensory stimulus but their findings suggest that the outcome could be reversed if the instructions were reversed if subjects were

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page J42

instructed to direct attention away from a cutaneous site where a noxious stimulus was being applied if they were instructed to relax close their eyes and concentrate on the play of phosphenes in the visual field as the behaviorally significant sensory stimulus then it would be reasonable to expect that the flow of blood would decrease to the somatosensory neurons linked with the cutaneous stimulus and that the flow of blood would increase to the visual cortices The decrease in blood flow to somatosensory neurons implies less neuronal activity which implies that fewer signals are being sent forward to the anterior CG than would have been sent if instead the subject were treating the touch as the behaviorally significant sensory stimulus If fewer pain signals arrive at the anterior it is reasonable to infer that the conscious experience of pain will be muted by the diversion of attention to internal visual stimuli

Differential impact of sleep rhythms in the visual and nonvisual thalamus There is another mechanism that might also contribute to the analgesic effect of inducing sleep rhythms PET studies show that

the thalamus is involved in the relay of nociceptive signals to the cortex63 although some confusion remains about which kinds of signals are relayed by which subregions in the thalamus62 One thalamic site clearly identified by anatomical studies as a relay for nociceptive signals is the ventroposterior lateral nucleus (VPL)69 If synchronous sleep rhythms are active in the thalamus we can reasonably expect that the VPL will itself be entrained by synchronous oscillations and that it will relay the sleep rhythms to somatosensory cortices Relay neurons in the VPL are not stimulated by feedback from eye movements and fixation as are relay neurons in the LGN which suggests that sleep rhythms may impede the relay of nociceptive signals via the VPL but not the relay of visual signals via the LGN

Brain waves associated with anesthesia and NREMS The hypothesis presented here-that consciousness can be preserved despite the presence of NREMS activity-is consistent with a recent report that the kinds of fast brain waves which are normally associated with conscious states are also present during NREMS and anesthesia two states which were thought to involve minimal brain activityJo Another recent study found that there is a close resemblance between the slow brain waves that appear during NREMS and those that appear during certain types of anesthesia71

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 143

bull bull bull

CONCLUSION

In this paper we have presented evidence supporting the hypothesis that phosphene images can be generated as an epiphenomena of thalamic spindle bursts and delta wave activity normally associated with NREMS The prereqshyuisites for inducing these sleep rhythm phosphenes are relaxed immobile expectancy sustained convergence and attentive fixation of an undifferentiated visual field Our hypothesis provides a necessary and sufficient explanation for the authors induction of phosphenes and perhaps also for the generation of phosphenes reported to appear spontaneously during the drowsy transition to sleep (hypnagogic states) during sensory deprivation or during certain kinds of prayer or meditation all of which involve a similar state of relaxed immobile expectancyJ2

CORRESPONDENCE Philip T Nicholson bull 52 Norfolk Road bull Chestnut Hill MA 02167

REFERENCES amp NOTES

1 M 1 Posner Modulation by Instruction Nature 373 (1995) pp 198-199 2 J Reissenweber E David amp M pfotenhauer Investigations of Psychological Aspects of

the Perception of Magnetophosphenes and Electrophosphenes Biomedizinische Tecknik 373 (1992) pp 42-45

3 S M Kosslyn W L Thompson 1 J Kim amp N M Alpert Topographical Representations of Mental Images in Primary Visual Cortex Nature 378 (I995) pp 496-498

4 P E Roland amp B Gulyas Visual Memory Visual Imagery and Visual Recognition of Large Field Patterns by the Human Brain Functional Anatomy by Positron Emission Tomography Cerebral Cortex 51 (1995) pp 79-93

5 H Benson The Relaxation Response (Morrow New York NY 1975) 6 ] H Schultz amp W Luthe Autogenic Training a Physiological Approach to Psychotherapy

(Grune amp Stratton New York NY 1969) 7 E Jacobson Progressive Relaxation (University of Chicago Press Chicago IL 1938) 8 M A Steinmetz BC Motter C] DuffY amp V B Mountcastle Functional Properties

of Parietal Visual Neurons Radial Organization of Directionalities Within the Visual Field Journal ofNeuroscience 71 (1987) pp 177-191

9 R R Edelman Magnetic Resonance Imaging of the Nervous System Discussions in Neuroscience 71 Elsevier Science Amsterdam (I990) also J H Newhouse amp ] I Wiener Understanding MRI 1st Ed (Little Brown Boston MA 1991)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 144

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

Table I Excerpts from self-reports of light visions by religious mystics

HEBREW MYSTICS the appearance of the wheels was like the gleaming of beryl and the four had the same form

their construction being something like a wheel within a wheel Ezekiel like a dome shining like crystal spread out about their heads And above the dome something

like a rhrone in appearance like sapphire Ezekiel a round Iodder like a full sphere rolling back and forth before him bright blue R Abulafia A glowing light clear brilliance A purple light that absorbs all lights R Moses de Leon

HINDU AND BUDDHIST MYSTICS a perfectly round beautiful deep-blue shape of a size appropriate to the center of a mandala as

if exquisitely painted of extreme c14rity Tsong Khapa a luminous revolving disc studded with lights a lotus flower in full bloom Gopi Krishna both my eyes became cemered When this happened a blue light arose in my eyes like

a candle flame without a wick and stood motionless in the ajna chakra S Muktananda

MUSLIM MYSTICS [like] chandelierssublime lights [like] stars moon or the sun Sharafuddin aI-Maneri its color is deep blue it seems to be an upsurge like water foom a spring Najmoddin Kobra visualize yourself as lying at the bottom of a well [looking up at the light of the opening] and

the well in lively downward movement Najmoddin Kobra the color green is the suprasensory uniting all the suprasensories Alaoddawleh Semnani the light rises in the Sky of the hean taking the form of light-gilling moons Najm Razi

CHRISTIAN MYSTICS his own state at prayer resembles a sapphire it is as clear and bright as the sky Evagrius descending like a bright cloud of mist like a sun round as a circle Simeon Neotheologos saw something in the air near him He did not understand the rype of thing but in some ways

it appeared to have the form of a serpent with many things that shone like eyes although they were not eyes Ignatius of Loyola

the soul puts on a green amilia [cape worn on shoulders beneath armor] John of the Cross [the almilla is like a helmet which] coverS all the senses of the head of the soul It has one

hole rhrough which the eyes may look upwards John of the Cross a round thing about rhe size of a rixdaier all bright and clear with light like a crystal H Hayen I saw a bright light and in this light the figure of a man the color of sapphireblazing with a

gentle glowing fire the three were in one light Hildegard von Bingen saw a b14zing fire incomprehensible inextinguishable with a flame in it the color of the sky

Hildegard von Bingen saw placed beneath her fuet the whole machine of the world as if it were a wheel She saw herself phced

above it her eyes of contemplation magnetized towards the incomprehensible Beatrice of Nazareth I saw the eyes I do not know if I was asleep or awake Angela of Foligno kind of sunlit winged being like a childs head beneath two little wings Abbess Thaisia laquobullbull round patterns small circles would expand and eventually dissipate only to be followed by other small

circles of light Philip St Romain an extraordinary circle of gold light pulsating against a deep violet background There were

always four or fille As soon as one would fode another would appear Philip St Romain

middotItalics added to mark words referring to (l) rings appearing in sets of four (2) amorphous shapes such as clouds or flames (3) circular or eye-like shapes (4) colors from the center of the visible spectrum (gold yellow yellow-green green bluish green) and (5) colors from the lower end of rhe visible spectrum (blue purple violet)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 124

cell membranes (Vm) has already begun to drop (hyperpolarize) in the thalamic reticular nucleus (RTN) a thin sheath of GABAnergic inhibitory neurons that acts as a pacemaker When the Vm of RTN cell membranes drops to approximately V m -60 millivolts (mV) RTN cells stop firing single spikes which are associated with waking states and instead begin firing highshyamplitude 7-14 Hertz (Hz) spike-bursts These bursts wax and wane over 1 to 3 seconds-hence the name spindle -and recur at 3 to 10 seconds Spindle volleys are relayed across the cortical mantle by thalamocortical (TC) sensory relay cells In human studies the primary criterion for onset of the first fullyshyestablished episode of NREMS or stage 2 sleep is the presence of globalized spindles in the cortical EEG

When spindle bursts from the RTN stimulate TC cells to fire in synchrony this synchronous bursting pattern overwhelms the normal capacity of TC cells to relay afferent sensory signals The loss of consciousness at the onset of stage 2 NREMS is thought to be caused by this blocking effect 21

While the RTN is firing spindle bursts through the thalamus another process is activated in the cortex large numbers of cells across the cortical mantle begin to oscillate at a very low frequency laquo 1 Hz)

The cortical slow rhythm referred back to the thalamus via corticothalamic circuits intensifies the hyperpolarizing effect of the RTN spindle bursts on TC cell membranes When V m -75 mV the TC cells begin to generate their own intrinsic calcium currents which further increases hyperpolarization At V m -90 mV the RTN neurons stop firing spindle bursts The TC cells continue to fire low-threshold calcium spikes in patterns which are controlled by the cortical slow rhythm The interaction of these two oscillations generates the delta waves (1 to 4 Hz) which are associated with stage 2 NREMS

In a study of sleep rhythms using the cortical EEG Uchida Atsumi and Kojima found that the mean number of spindles required to induce delta wave activity (that is to induce Vm = -90 mY) is 478 plusmn 162 spindles (from 3 to 7 spindles)22 The mean number of spindles in a volley remains the same for a single individual over multiple trials

Based on the consensus scenario for generation of NREMS we can predict that a phosphene image generated as an epiphenomenon of a thalamic spindle

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 125

Table II Dara show rhe degree of correspondance berween rhe pulse panerns of rhalamic spindles based on intracellular research and rhe sparioremporal panerns of receding annuli phosphenes induced by rhe author using a rechnique of self-hypnosis

Receding annuli phosphenes Thalamic spindle bursrs

Mean number of signals 4 annuli 487 (plusmn 16) bursrs

Sparial exrension vs Thin band 1 - 3 seconds durarion of signal ( 05 -15 cm)

Periodicity of signals 5 seconds 3 - 10 seconds

Simultaneity in LGNs Yes Yes

Point of entry Peripheral VF Ventral amp lareral LGN

Trajecrory Bilareral concentric Unknown

Rare of flow Cons rant rare Unknown

Signal-ro-noise rario High High (shorr bursrs) (sharp brighr discrere)

Termination of sequence Mrer 4 signals Mrer 487 (plusmn 16) signals

will present the following characteristics (1) a high-definition burst-like signal (2) that recurs within 3 to 10 seconds (3) that follows a trajectory compatible with having entered the LGN from the RTN (4) that has a predictable mean for the individual subject and a range that falls somewhere between 2 to 7 annuli and (5) that the spindles will terminate automatically

The temporal patterns of receding annuli and thalamic spindle bursts are similar Table II illustrates the close match between the timing of receding annuli phosphenes and thalamic spindle bursts The most striking similarities are the mean number of signals required to induce termination (4 annuli versus 487 spindles) and the interval between signals (5 seconds for annuli versus 3shyto-lO seconds for spindle bursts) Neither alpha theta nor beta waves present this kind of stereotyped temporal pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 126

T he spatial features of receding annuli are functions of geniculate anatomy A spindle burst moving through the LGN to the cortex will acquire certain distinctive spatiotemporal characteristics because of the

unique curvilinear and laminar anatomy of the LGN A drawing of a macaque LGN based on a clay model constructed by Le Gros Clark23 is shown in Figure 3 The primate LGN is composed of six sheets of cells or laminae that fold over a central hylus In macaques the hylus rises steeply as it extends rostrocausally forming a high arch at the posterior pole in humans the hylus is much more shallow but the functional anatomy is thought to be essentially

23 24the same in both cases - The geometry of the arch forces each lamina to bend so as to constitute in effect one-half of a conical surface and each lamina with its hemi-conical shape contains visual relay cells representing the contralatshyeral half of the visual field (VF) Operating as a pair the complementary hemishycones of the right and left LGN form the functional equivalent of a single conical surface which represents the entire VE This conical geometry of the paired LGNs means a burst of otherwise formless excitation will acquire a distinctive shape as it propagates through the laminae of the LGN Imagine a horizontal section moving along the surface of a cone from base to apex that moving section forms an annulus that shrinks in diameter as it approaches the apex but retains its annular symmetry throughout its trajectory

Figure 3 also includes drawings that show how Connolly and Van Essen24

converted the 3-dimensional structure of lamina 6 the largest and most dorsal layer into a 2-dimensional map Connolly and Van Essen used data obtained by Malpelli and Baker25 to superimpose a grid that specifies the areas in lamina 6 that contain TC cells representing various degrees of isoeccentricity in the VE We will use this map at a later point to show how the movement of a spindle wave through a pair of LGNs correlates with what appears in the VE

The location of the RTN relative to the LGN is also shown in Figure 3 The RTN spindle pacemaker is a thin sheath of GABAnergic inhibitory cells that extends along the surface of the whole posterior ventral thalamus not just the LGN This extension brings the RTN into close proximity with the portion of the LGN (lateral wing) that protrudes out from the main body of the thalamus Some of RTN wraps around and beneath the ventral edges of the LGN26 The RTN comes closest to the LGN in two areas along the ventral edges of the longest laminae (lamina 6 and 1) and along the edge of the lateral

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 127

DORSAL POLE DORSALPOIEA B

L1 L4 L3 L

DORSAL POlE DORSAL POIE (FOVEA)

G LATERAL WING

25

DORSAL POL (FOVEA)

10 _DIAL

20 WING

~

wing These areas contain TC cells that represent the far periphery of the VE If a spindle burst enters the LGN at locations where laminae are in closest proximity to the RTN-along the ventral edges-then the discharge of TC cells will begin in the most ventral portions of the laminae the regions that represent the far periphery of the VE This matches the phosphene sequence observed by the author

Our hypothesis about how this proximity between RTN and LGN affects the trajectory of spindle waves is illustrated in Figure 4 We propose that it is not possible for the author to observe a thin annulus of phosphene sweeping in from all 3600 of the peripheral VF unless spindle bursts exhibit the following

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 128

Figure 3 [facing page Drawings of primate geniculate anatomy and functional anatomy relevant to the generation ofphosphenes (A) Anterior view ofa macaque monkey LGN based on a clay model reconstruction by Le Gros Clark 23 (B) Posterior view ofthe same model showing 6 laminae folded over a central hylus to form lateral and medial wings with the hylus arching steeply upward near the posterior pole to shape the laminae into layers of hollow half-cones nested together Note that the lateral wing of the LGN is slightly larger than the medial wing so that in situ the lateral wing protrudes out from the main body of the thalamus creating a small knob visible during dissection 26 (C) Schematic drawing of an oblique section through median axis (also adapted from Le Gros Clark13 showing how the laminae fuse together at the anterior pole The afferent ganglion cell axons that form the optic tract (OT) penetrate through the anterior surface to reach their target relay cells in the laminae (D) Drawing of the most dorsal lamina-layer 6--separated from the rest of the LGN The geometric shape is a hollow half-cone so that right and left LGNs placed back-to-back form in effect a single cone Note also the position ofthe RTN shown here as a striped bar relative to lamina 6 The position of the striped bar shows that the RTN makes direct contact with lamina 6 at the edge ofthe lateral wing and also along the ventral edges (E - F) Schematic drawings adapted from Connolly and Van Essen24 that show how a 3-dimensional lamina-lamina 6--can be transformed into a 2-dimensional triangular figure lamina 6 is removed and its wings unfolded (E) creating a slightly asymmetric triangular figure (F) which is adjusted to an oblong shape (G) in order to superimshypose a grid matrix with minimal distortion The grid plots locations of TC cells that represent various isoelevations and isoazimuths in the VF locations derived from the experimental observations published by Malpeli and Baker 25 Note the relatively large amounts of laminar surface allocated to central vision (0 0

- 30 0) as compared

to peripheral vision (30 0 - 80 0)

characteristics (1) Spindle bursts must move simultaneously through both geniculate nuclei This pattern of movement is consistent with anatomical studies in primates that found axonal projections linking the right and left RTNs27-28 and with experimental studies in cats that found spindles appearing simultaneously in both right and left thalami 29 (2) Spindle waves must enter the ventral edges of the LGN first and move ventrodorsally in a highly coherent pattern-moving in effect as a standing wave This pattern of movement is consistent with in vitro experiments using sagittal slices from a ferret LGN where spindle waves originated spontaneously at the edge of a slice in an area which contains cells that represent peripheral vision then propagated toward that area of the slice containing cells that represent central vision in the ferret 3o

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 129

VF

PG BIlateral receptive lleJd of PVN YI(j Inward dmKooflality Adapled

0-- from Mortgr at at (1987)

V1

ibull t bull

RTN t t t t t t 1middot3 SECOlO BURSTS OF 7middot14 HZ SPiKES RECURRNG EVERY 3 10 SECONDS

To our knowledge the LGN is the only anatomical structure in the visual system that has the capacity of passively forcing a wave of excitation to flow across a conical surface thereby generating the sensation of a phosphene annulus that retains its symmetry as it shrinks in diameter The retina has a circular anatomy but it is not likely that the mechanical deformation of the retina would produce a wave that began simultaneously in all 3600 of the retinal rim nor that the symmetry of annular wave would be preserved as it flows inward toward the foveal region

The hypothesis presented here-that there is a structure in the visual system that imprints a conical shape on standing waves that move through it-explains

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 130

Figure 4 facing page Schematic drawing of contemporaneous events in selected regions of the visual processing hierarchy (A) The left and right RTNs fire spindle bursts simultaneously (B) The bursts pass through the right and left geniculate laminae as standing waves of depolarization entering from the ventral edges and moving ventrodorsally in parallel In order for the phosphene annulus to appear to be flowing at a constant rate the spindle wave flowing through the LCN must expand in width as it ascends ventrodorsally so that by the time the fill-in disk appears-when the center 30deg of the VF is covered by the phosphene annulus-the spindle wave must have expanded enough to activate relay cells in the most dorsal 50 of lamina 6 (C) Signals representing two complementary hemi-annuli are kept separate in the primary visual cortices (area VI) (D) Signals representing the two hemi-annuli are integrated into signals of a single annulus when they reach area PC in the posterior parietal cortex where the receptive fields of single parietal visual neurons have the capacity to register bilateral signals that exhibit opponent vector movement (that is signals converging from opposite directions along the central axes-as if an object were moving away from the viewer)46 Neurons in area PC also integrate wavelength (color) signals from the extrastriate visual pathway with signals about brightness motion and depth from the parietal visual pathway to compose a representation of an object in space-in this case of an annulus that appears to recede 32

the authors experience during MRI when he observed a continuous succession of receding annuli every 2 seconds in this view the energy of the electroshymagnetic bombardment when released during precessional relaxation flows through the geniculate laminae in the same way that the RTN spindle bursts do that is as a standing wave and thus the visual epiphenomenon is the same in both cases if the subject keeps the eyes focused straight ahead and the attention fixated In a study of phosphenes evoked by electricity in conjunction with hallucinogenic drugs Knoll Kugler Hofer and Lawder found that each subject sees specific kinds of phosphene at different frequencies and that these frequency-specific images are stable enough to be reproduced after six months31

They conclude that the tunability of the electrical stimulation frequenshycies within the EEG range to various definable phosphenes requires the existence of a resonance system One mechanism contributing to that resonance system may be the functional anatomy of the LGN

The colors of receding annuli as functions of geniculate laminar anatomy The colors of receding annuli phosphenes are consistent with the patterns of discharge spindle waves can be expected to stimulate as they move through

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 131

geniculate laminae As shown in Figure 5 the six laminae differ (1) in the types of wavelength signals relayed (2) in physical size and (3) in the area of the VF represented 24-25 Only 4 out of 6 laminae Cparvocellular layers 3shy6) contain TC cells that relay wavelength signals the other 2 laminae (magnocellular layers 1 and 2) do not encode wavelength Among parvocelshylular laminae only lamina 6 the longest and most dorsal layer contains TC cells that can represent the far periphery of the VF (from 800 to 50deg of isoeccenshytdeity) therefore when the spindle wave enters the peripheral VF only those wavelengths relayed by lamina 6 will participate in composing a cortical lightness record (See Zeki)32

I n lamina 6 ganglion cell axons arriving from the retina carry two kinds of wavelength signals (1) center-ON signals from medium-wavelength cones (M-cone center-ON) and long-wavelength cones (L-cone centershy

ON)33-35 Using the cone spectral sensitivity curves (adapted from Marks et al 36) we average the wavelengths that elicit maximal responses for M-cones (535 nanometers) and L-cones (520 nm) which yields a mean wavelength value of 550 nm In humans this wavelength generates a sensation of green or yellowshygreen the sensation observed by the author

As the spindle burst moves ventrodorsally it reaches the dorsal areas in the geniculate laminae which contain TC cells representing the central 0deg to 20deg of isoeccentrieity in the VE All 4 parvocellular laminae have TC cells which are potentially capable of representing this central region of vision but the authors observation that the color of the filling-in disk changed from green to blue implies that in the early years of phosphene induction the spindle wave must have remained close to the surface of the LGN stimulating only laminae 5 and 6 which generates a sensation of yellow-green When the fill-in disk was observed to change color from green to blue the spindle wave must have been rechanneled so that it began to penetrate below laminae 5 and 6 and to activate laminae 3 and 4 the only laminae that relay blue-sensitive signals (Sshycone center-ON signals)3 In light of the authors MRI experience it seems likely that a spindle wave requires a minimum of 2 seconds to reach the blueshysensitive cells of laminae 4 therefore during MRI when the receding annuli disappeared after 2 seconds half the normal duration the fill-disk had a green color even though it had long since change to blue in other induction settings with a 4-second trajectory

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 132

A REPRESENTATION OF THE VISUAL FIELD IN EACH LAMINA

orooqUtftc O-u OCIJ1SALfIOLI (I01flAj

0

10

20

30

40 n50 Of

60

70

20 loO 1Mgr_ II~ o UIpoundAS65 mn1MY-o actlvncL ~~~r

Jll-COMcetlImiddot~

II LAYERSU 3 GatQYancetl~ (1) ucon ceom-oyenF (2)l~cen()FF 3) ~ cenloH

II~ cng1loqctWIIIfNla

iICINe -- (t81Otdb1t1d~OH (2)~

80

B CONE SPECTRAL SENSITIVITY CURVES

S-COHS

WAVIlLllNG1llS OF UGHT IH NANOMllTERS (NM)

Figure 5 Phosphene color as a function of ganglion cell distribution in parvocellular laminae (Aj Schematic drawing ofthe proportion ofthe VF represented in each laminae The proportions shown here are based on the work of Connolly and Van Essen24 The

far periphery of vision (50 0 to 80 0 of isoeccentricity) is represented in only two laminae-laminae 1 and 6-and of these two only lamina 6 is a parvocelLular lamina capable ofencoding wavelength signals Therefore only those wavelengths relayed by lamina 6 will participate in forming a cortical lighmess record for the far periphery of the VP (B) Cone spectral sensitivity curves (adapted from Marks et al)36 Using these cone sensitivity curves we can estimate the sensation stimulated by a spindle wave moving through lamina 6 by averaging the wavelengths that elicit maximal responses for M-cones (535 nanomeshyters) and L-cones (520 nm) which yields a mean wavelength value of550 nm In humans this generates a sensation of green or yellow-green the sensation observed by the author when the receding annulus enters at the far periphery of the VP For a calculation of the cortical lightness record when a spindle wave moves through 20deg to 0deg ofthe VF stimulating all 4 parvocelfular laminae see the text and Figure 6

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 133

Once the spindle wave penetrates to laminae 3 and 4 it may activate all 4 parvocellular laminae stimulating TC cells to send contradictory wavelength signals for the same retinotopic location the signals sent from laminae 4 and 3 will encode blue light (S-cone center-ON plus M-cone center-OFF and Lshycone center-OFF) while the signals sent from laminae 5 and 6 encode yellowshygreen light (M-cone center-ON plus L-cone center-ON) This kind of contrashydiction does not occur in normal retina-based perception where light energy striking the retina is structured by the retinas center-surround and colorshyopponent organization to encode only one set of wavelength signals for each spatial locus 32 In Figure 6 we estimate the cortical lightness record that results when contradictory wavelength signals compete to be represented in consciousshyness Our calculations suggest that the outcome will be a mean wavelength which in humans elicits a dark blue or violet sensation

PART II AMORPHOUS PHOSPHENES amp THALAMIC DELTA ACTMTY

M echanisms controlling the transition from spindle bursts to delta activity In the consensus scenario for the generation of NREMS16-20 we noted that the RTN shifts to firing spindle bursts

when polarization of thalamic cell membranes drops to V m = - 60 mV At the same time cortical cells begin oscillating with a synchronous slow rhythm laquo 1 Hz) Both processes further decrease the Vm of TC cell membranes When Vm = - 75 mY TC cells begin to generate their own intrinsic calcium currents which also decreases V m At V m = - 90 mV RTN neurons stop firing spindle bursts At the same time the TC cells begin firing low-threshold calcium spikes in alternation with after-hyperpolarizations (LTS-AHP) Because sensory relay neurons in the LGN are not linked to one another by locally projecting axons the firing of one TC cell does not excite its neighbor However a lack of local connectivity does not mean that TC cells occupying the same laminae release their AHP-LTS calcium spikes in a random distribshyution rather spikes are released simultaneously by groups of cells in synchrony with the advent of the cortical slow wave In effect the distribution of LTSshyAHP spikes firing in the LGN is determined by the spatial propagation of the cortical slow wave Thus the delta wave (1 to 4 Hz) activity detected by cortical EEG during NREMS is a product of the interaction between the AHP-LTS calcium spikes released by TC cells and the cortical slow rhythm

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 134

CORTICAL PROCESSING OF CONTRADICTORY

WAVELENGTH SIGNALS

KEY _ Cells firing

cJ Cononol firing

Assume that as a spind6e wave moves through the LGNlt fires simultaneously aU the TC cells that represent a particular reUnoshytopic locus (x y) in each of the six laminae As a result cortical cells engaged In the higher level processing of visual signals will receive more wavelength signals representing retina locus (x y) than are generated by normal perception laquo and some of these afferent wavelength signals may contradict other signals arriving simultaneously

CORTICAL LIGHTNESS RECORD SlgnalSell

Intemal contradictions not congruent wilt pre

SmiddotON eristing neuron neta

s bullbull M-ON LmiddotON

3 bullbull M-OFF + L-OFF

a-ON 12

ROD-ON

No Internal eonlradlemiddot

--------1I =~8b~~~~~~~t signals

3+4

~ --OFF Excludes 6 Of 7 $J9n18

1+2 B-ON I

IWmiddotHmiddotI Signal Sell

1111111 No Intern1 conlrfldlcshy lion

Exelvdta 4 out of 7 efshy

bullbullbull bullbullbull ferant signals

No Intern1 contradic_ tionnee S-ON BshyOH and ROO-ON can all be coacllve at low lImlnance levels nef Ihe rod-eone break

ExchJde$ only 2 Ollt of 7 afferent signals

Figure 6 Selection of competing wavelength signals based on neuronal group selection This thought experiment is based on Edelman sconcept ofneuronal group selection 73 We assume that all possible combinations ofsignals will form sets and that all signal-sets will compete to make the most efficient match with pre-existing neuromd networks that have been forged over years ofnorma reti1U1-based perception We also assume that pre-existing neural networks are most likely to expedite those sets that satisfY 2 criteriI (J) the signals in a set do not contradict each other and (2) fower signals are excluded than in the other sets that satisfY the first criterion In our analysis Set 4 wins the competition because it does not contain internal contradictions and excludes fower signals (2 out of 7) than Set 3 excludes (4 out of7) It is not an internal contradiction that Set 4 contains both rods and cone Signtlls in normal retina-based perception when luminance levels approach the rod-cone break S-cone center-ON receptors send signas as do rod receptors and there is even evidence that rod activity may actually drive S-cone activity even after luminance levels foIl below the rod-cone break74 To calculate the cortical lightness record for Set 4 we average the wavelength that elicits maximal responses foom rods (511 nm) and for Sshycones (430 nm) which yields a mean wavelength of 470 nm which in humans results in a dark-blue or violet sensation

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 135

The cortical slow rhythm is an example of a generic pattern of neuronal excitashytion that occurs in large networks of neurons linked by local projections A recent experiment by Maeda Robinson and Kwana38 shows that networks of locally-connected neurons spontaneously generate periodic synchronized bursts of calcium transients that propagate across the network in an expanding spatial wave a pattern that represents a stable mode of firing towards which these neuronal networks relax following perturbations for example by electronic stimulation or by drugs Understanding the characteristics of these waves is an important prerequisite to understanding the mechanisms that produce the amorphous phosphene images as a visual epiphenomenon

To study the spontaneous periodic synchronized bursts the researchers prepared cultures of dissociated cortical neurons and allowed them to mature for several days in vitro (DIV) After 3 to 4 DIV when concenshy

trations of extracellular magnesium were low electrodes began to detect spontaneous synchronized bursts of low frequency calcium transients (between 01 and 1 Hz) that originated in different locations on the sheet every 10 to 20 seconds and spread across the sheet of cells at a relatively slow speed averaging 50 mmsecond The researchers could not predict where a wave would originate or where it would expand rather the initiation and expansion of waves was generated by spatial and temporal summation of a continuous random background of synaptic inputs including miniature spontaneous synaptic events but the pattern was not random since waves propagated sequentially from electrode to electrode as each local group of neurons charges up its neighboring nontefractory areas rather than in a random sequence of regions38

The excitability of the cells in the sheet determines the probability first that there will be a synchronous burst and second that it will spread in a particshyular direction Cells become more excitable as the cultures mature which means the refractory intervals between successive bursts were much shorter in mature cultures (gt 30 DIV) than in early cultures laquo 7 DIV) Some cells became so insensitive to inhibition that they continued to fire bursts even when extracellular concentrations of magnesium were relatively high Finally there were refractory periods of 5 to 10 seconds during which no bursts occurred even when an electrical stimulus was applied This refractory interval for cultured networks is slightly longer than the refractory interval observed of the cortical slow wave in vivo which 25 to 4 seconds 18- 19

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 136

Based on the observations about cortical slow waves we can predict that phosphenes generated as epiphenomena of delta wave activity will present the following signal characteristics (1) signals that appear at unpredictable locations in the VF (2) signals that expand and diverge asymmetrically following unpredictable trajectories which may encompass large areas of the VF (3) signals that move relatively slowly (50 mmsec) (4) signals that recur with a period of 2 to 4 seconds reflecting entrainment by the cortical slow wave (5) signals that do not terminate automatically after a predictable number of cycles

The spatial patterns of phosphene mists and thalamic delta waves are similar The spatiotemporal characteristics of amorphous phosphenes match the pattern of wave propagation associated with periodic spontashy

neous synchronized bursts in large neuron networks the amorphous phosphenes enter the visual field at unpredictable locations expand and diverge asymmetrically with a slow steady rate of flow follow trajectories that are unpredictable and exhibit a refractory interval The amorphous mists do appear to have a periodicity although the author is unable to sustain the vision while also counting the seconds therefore he is unable to determine if it compares to the period of the cortical slow wave (25 to 4 seconds) but his impression is that it feels roughly the same as as with receding annuli which recur at 5 seconds Also the refractory interval feels as if it decreases as the induction session is extended These similarities suggest that the amorphous phosphenes are generated by stage 2 NREMS delta wave activity which is an activity governed by the reverberation of the cortical slow wave in thalamoshycorticothalamic circuits The cortical slow wave is referred to the LGN where it modulates the firing of visual relay cells in the laminae and since relay cells do not have local dendritic connections the expansion of a wave of depolarshyizations moving from one relay cell to the next across in the laminar surface will mirror at least in part the expansion of the cortical wave that is spreading contemporaneously through locally-connected cortical cells

PART III RETENTION OF CONSCIOUSNESS

In a normal transition to NREMS the volley of synchronous spindle bursts that marks the onset of stage 2 NREMS overwhelms the normal firing pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 137

of thalamocortical cells preventing their relay of afferent sensory signals and inducing a loss of consciousness21 But the loss of consciousness cannot be timed precisely using cortical EEG the thalamus is too remote for the onset of spindling to be reliably detected by scalp electrodes39 In experiments with cats where electrodes could be implanted in the thalamus researchers found that spindling often reached peak levels of activity in the thalamus-a level of activity consonant with stage 2 NREMS-at a time when the cortical EEG was still showing intermittent desynchronizations a pattern characteristic of the drowsy stage 1 transition not a fully-established stage 2 NREMS episode4o

In other words there is a short period of time in which the synchronous rhythms of stage 2 NREMS are installed in the thalamus but not in the cortex where cortical neurons continue to depolarize in response to afferent sensory signals

T his finding suggests a possible explanation for the authors ability to retain consciousness while spindle bursts are sweeping through the LGN if he is able to extend the duration of this time lag between

the onset of spindling in the thalamus and spindling in the cortex if he is able to stimulate the visual cortices in such a way that they continue to depolarize then he may be able to keep on processing visual signals-to remain visually aware-even after the non-visual thalamus and non-visual cortex become entrained by synchronous sleep rhythms The authors induction technique includes several behaviors which are known to enhance the responsiveness of visual neurons-eye movements attentive fixation and an attitude of expectancy

Effects of eye movements and attention on the LGN Sustained convergence causes periorbital proprioceptors to send excitatory feedback directly to the LGN41 Also convergence further enhances the excitability of geniculate cells by stimulating the superior collicus (SC) which sends its own excitatory signals to the LGN42-43 These signals from the SC are known to selectively enhance the excitability of visual relay cells that represent the periphery of vision44 We know in the authors case that the SC is being stimulated because he is able to keep on fixating an ability which would normally be lost during the transishytion to NREMS45 The ability to fixate can be retained however if the SC is stimulated (even if stimulated during NREMS)46

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 138

Effects of eye movement attention and expectancy on the primary visual cortex The PET study of mental imagery by Kosslyn et al 3 showed that even a baseline resting state of relaxed immobile expectancy can generate signifishycant increases in neuronal activity in the primary visual cortices Further increases can be induced by sustained eye movements

A sustained convergence will release a stream of ponto-geniculo-occipital (PGO) waves These PGO waves called eye movement potentials or EMPs last only as long as the eye movement1747 whereas the PGO waves associated with rapid-eye-movement sleep (REMS) fire continually for the duration of the REMS episode Both REMS-related PGO waves and EMPs have the same desynchronizing effect on the visual pathways they move through the LGN depolarizing the thalamocortical cells which relay the signals to cortical neurons The responsivity of neurons in the primary visual cortices is enhanced by the stimulation of PGO waves 1747-49 If the passage of EMPs causes the genicushylate relay cells and their cortical targets to depolarize regularly then a volley of 4 spindle bursts moving through the same pathways will register as just another series of depolarizations in effect the spindle bursts are processed by the visual system as if they were sensory signals sent from the retina rather than an event stimulated by endogenous mechanisms

T he impact of eye movements and ftxation on the parietal visual cortex Convergence and attentive fixation will also enhance the responsiveness of light-sensitive parietal visual neurons (PVNs) in area PG of the

posterior parietal cortex 50 In experiments where monkeys are trained to fix their attention on a screen-and to keep on fixating even if no targets appearshythe excitability of these light-sensitive PVNs increases by as much as 350 51

52-53Responsiveness is also facilitated by the angle of gaze Also area PG is the first region in the visual pathways containing individual neurons with the capacity to respond to large bilateral stimuli moving in opposite directions along the central meridians of vision (opponent vector motion) 853-55 Facilitation of PVNs in area PG has the effect of sensitizing the subject to bilateral opponent vector motion and this is especially true if the movement appears in the periphery of the VE 8

Intracortical ampliftcation and feedback to the LGN When PGO waves and signals from the SC arrive in the primary visual cortex they may be relatively weak however weak signals can be amplified by reverberating in large networks

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 139

of cortical cells linked by local projection 56 There are nine times as many excitatory links among cortical cells as there are projections from the visual cortex to the LGN an imbalance which suggests leads Suarez Koch and Douglas to propose that geniculate input provides only a minor fraction of the excitatory input the majority originating in neighboring and recurrently connected cortical cells57 If the excitabiliry of cortical neurons is slightly higher than normal then this process of amplification may continue even after the LGN signals that initiated the reverberation are no longer being transmitted by the LGN ( a hysteretic mode of operation) 57

Feedback from hyperexcited cortical neurons will stream back to the LGN via corticogeniculate projections which outnumber geniculocortical projections ten-to-one One effect of this feedback is that the LGN is

able to absorb large amounts of information flowing back from the cortex 58

As signals reverberate back and forth in thalamocorticothalamic circuits a matching process takes place those geniculate relay cells that fire in patterns consistent with the firing patterns of active cortical cells will have their responshysivity enhanced while those geniculate cells that fire in patterns not consistent with cortical cells will be suppressed 59

Preservation of consciousness by selective facilitation of the visual pathways By combining all of the facilitatory effects produced by the authors eye movements and attentive fixation-(l) stimulation of the LGN by feedback from periorbital proprioception both directly and indirectly via the SC (2) the release of PGO waves (EMPs) that facilitate neurons in the LGN and primary visual cortex as they pass (3) the facilitation of the primary visual cortex by a state of relaxed immobile expectancy (4) attentive fixation and angle of gaze that facilitate PVNs in area PG (5) intracortical amplification of signals received from the LGN and (6) corticogeniculate feedback that stimulates the LGN-we delineate a circuit of enhanced excitability that extends from the LGN through the post-geniculate visual heirarchy to area PG where signals are integrated into representations of objects

The hyperexcitability of neurons all along the post-geniculate visual pathways creates conditions in the visual cortices which are similar to those present during EEG-desynchronized states of waking and REMS Therefore neurons in the visual pathways are too excitable to be entrained by synchronous bursting

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 140

patterns when spindle waves move through them instead the spindle bursts stimulate visual neurons to depolarize and then recover as happens in response to afferent sensory signals during waking states It is important to note that for this to occur none of the constituent neuron assemblies is required to perform an abnormal operation the abnormality is a function of the authors intent to activate contemporaneously neuron assemblies that would not normally be co-activated

PART IV HYPNOTIC ANALGESIA

Manipulation of spatial attention as a method for alleviating pain sensations In a theoretical article on the neurophysiology of hypnosis Crawford and Gruzelier60 propose that variations in hypnotizability are function of variability in the efficiency of the frontolimbic (anterior) attentional system in humans high-hypnotizables are better able to sustain focused attention on a task and to ignore extraneous stimuli than are low-hypnotizables

I na related empirical study that compares the use of attention by subjects with high versus low hypnotizability Crawford Brown and Moon61 report that highly hypnotizable persons continue to show physiological reactivity

while cognitively not perceiving the painful stimuli Through disattentional processes they can dissociate themselves from the awareness of pain The authors phosphene induction behaviors-and the cutaneous analgesia he experishyences-appear to involve the same kind of behaviors that is a mobilization of frontolimbic attention used to withdraw attention from external stimuli and to concentrate it on internally-generated phosphene images This suggests the hypothesis that the mechanisms that generate phosphenes might also produce hypnotic analgesia There are several ways that visual signals and pain signals might interact to produce this analgesia

Competition between pain and vision signals for limbic registration The fully-developed sensation of pain requires integration of rwo kinds of informashytion Signals that encode the location and intensity of a noxious stimulus (nociceptive signals) are relayed via the thalamus to the somatosensory cortices which registers only the sensory-discriminative aspects of pain perception62 before reaching consciousness the nociceptive signals must be sent to the limbic

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 141

system where they are linked with signals from long-term memory that encode the affective significance the stimulus has acquired for that individual Studies of brain metabolism show this linking of somatosensory information with limbic associations takes place in the anterior cingulate (CG) and anterior insula62-64

PET studies also show that the anterior CG is activated when subjects shift their spatial attention in response to expectations as to where

66stimuli will next appear65- This is precisely what takes place during the state of immobile expectancy that induces phosphenes Since visual signals and nociceptive signals both require limbic enhancement which is only possible if they get access to the anterior CG there might be conditions in which the two types of afferent sensory signals have to compete for that access In a theoretical article on the mechanisms of attention Posner and Rothbart67

propose that visual signals can interfere with nociceptive signals by blocking access to the anterior CG As behavioral evidence they cite studies showing that when young infants make distress calls they can be distracted by the presentation of a new visual stimulus We have shown the evidence of such control at about three months Orienting to visual events can be employed to quiet or calm negative vocalizations However the distress appears to be maintained and reappears when the infants attention to the stimulus is reduced Caregivers also report the use or visual orienting to block overt manifestations of distress at about this age 67

The effects of disattention on the somatosensory cortices If there is a competition between visual signals and nociceptive signals for access to the anterior CG it is likely that the competition will be affected by the relative volume of signals received A recent study suggests that focusing attention on internally-generated visual stimuli may reduce the number of nociceptive signals relayed by the somatosensory cortices Drevets Burton Videen Snyder Simpson and Raichle68 have shown that the mere anticipation of a touch at a specific cutaneous site increases the flow of blood to those cortical somatosenshysory neurons that are linked with that site where touch is expected and decreases the flow of blood to neurons linked with sites where touch is not expected In this experiment the researchers designated touch as the behaviorally significant sensory stimulus but their findings suggest that the outcome could be reversed if the instructions were reversed if subjects were

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page J42

instructed to direct attention away from a cutaneous site where a noxious stimulus was being applied if they were instructed to relax close their eyes and concentrate on the play of phosphenes in the visual field as the behaviorally significant sensory stimulus then it would be reasonable to expect that the flow of blood would decrease to the somatosensory neurons linked with the cutaneous stimulus and that the flow of blood would increase to the visual cortices The decrease in blood flow to somatosensory neurons implies less neuronal activity which implies that fewer signals are being sent forward to the anterior CG than would have been sent if instead the subject were treating the touch as the behaviorally significant sensory stimulus If fewer pain signals arrive at the anterior it is reasonable to infer that the conscious experience of pain will be muted by the diversion of attention to internal visual stimuli

Differential impact of sleep rhythms in the visual and nonvisual thalamus There is another mechanism that might also contribute to the analgesic effect of inducing sleep rhythms PET studies show that

the thalamus is involved in the relay of nociceptive signals to the cortex63 although some confusion remains about which kinds of signals are relayed by which subregions in the thalamus62 One thalamic site clearly identified by anatomical studies as a relay for nociceptive signals is the ventroposterior lateral nucleus (VPL)69 If synchronous sleep rhythms are active in the thalamus we can reasonably expect that the VPL will itself be entrained by synchronous oscillations and that it will relay the sleep rhythms to somatosensory cortices Relay neurons in the VPL are not stimulated by feedback from eye movements and fixation as are relay neurons in the LGN which suggests that sleep rhythms may impede the relay of nociceptive signals via the VPL but not the relay of visual signals via the LGN

Brain waves associated with anesthesia and NREMS The hypothesis presented here-that consciousness can be preserved despite the presence of NREMS activity-is consistent with a recent report that the kinds of fast brain waves which are normally associated with conscious states are also present during NREMS and anesthesia two states which were thought to involve minimal brain activityJo Another recent study found that there is a close resemblance between the slow brain waves that appear during NREMS and those that appear during certain types of anesthesia71

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 143

bull bull bull

CONCLUSION

In this paper we have presented evidence supporting the hypothesis that phosphene images can be generated as an epiphenomena of thalamic spindle bursts and delta wave activity normally associated with NREMS The prereqshyuisites for inducing these sleep rhythm phosphenes are relaxed immobile expectancy sustained convergence and attentive fixation of an undifferentiated visual field Our hypothesis provides a necessary and sufficient explanation for the authors induction of phosphenes and perhaps also for the generation of phosphenes reported to appear spontaneously during the drowsy transition to sleep (hypnagogic states) during sensory deprivation or during certain kinds of prayer or meditation all of which involve a similar state of relaxed immobile expectancyJ2

CORRESPONDENCE Philip T Nicholson bull 52 Norfolk Road bull Chestnut Hill MA 02167

REFERENCES amp NOTES

1 M 1 Posner Modulation by Instruction Nature 373 (1995) pp 198-199 2 J Reissenweber E David amp M pfotenhauer Investigations of Psychological Aspects of

the Perception of Magnetophosphenes and Electrophosphenes Biomedizinische Tecknik 373 (1992) pp 42-45

3 S M Kosslyn W L Thompson 1 J Kim amp N M Alpert Topographical Representations of Mental Images in Primary Visual Cortex Nature 378 (I995) pp 496-498

4 P E Roland amp B Gulyas Visual Memory Visual Imagery and Visual Recognition of Large Field Patterns by the Human Brain Functional Anatomy by Positron Emission Tomography Cerebral Cortex 51 (1995) pp 79-93

5 H Benson The Relaxation Response (Morrow New York NY 1975) 6 ] H Schultz amp W Luthe Autogenic Training a Physiological Approach to Psychotherapy

(Grune amp Stratton New York NY 1969) 7 E Jacobson Progressive Relaxation (University of Chicago Press Chicago IL 1938) 8 M A Steinmetz BC Motter C] DuffY amp V B Mountcastle Functional Properties

of Parietal Visual Neurons Radial Organization of Directionalities Within the Visual Field Journal ofNeuroscience 71 (1987) pp 177-191

9 R R Edelman Magnetic Resonance Imaging of the Nervous System Discussions in Neuroscience 71 Elsevier Science Amsterdam (I990) also J H Newhouse amp ] I Wiener Understanding MRI 1st Ed (Little Brown Boston MA 1991)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 144

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

cell membranes (Vm) has already begun to drop (hyperpolarize) in the thalamic reticular nucleus (RTN) a thin sheath of GABAnergic inhibitory neurons that acts as a pacemaker When the Vm of RTN cell membranes drops to approximately V m -60 millivolts (mV) RTN cells stop firing single spikes which are associated with waking states and instead begin firing highshyamplitude 7-14 Hertz (Hz) spike-bursts These bursts wax and wane over 1 to 3 seconds-hence the name spindle -and recur at 3 to 10 seconds Spindle volleys are relayed across the cortical mantle by thalamocortical (TC) sensory relay cells In human studies the primary criterion for onset of the first fullyshyestablished episode of NREMS or stage 2 sleep is the presence of globalized spindles in the cortical EEG

When spindle bursts from the RTN stimulate TC cells to fire in synchrony this synchronous bursting pattern overwhelms the normal capacity of TC cells to relay afferent sensory signals The loss of consciousness at the onset of stage 2 NREMS is thought to be caused by this blocking effect 21

While the RTN is firing spindle bursts through the thalamus another process is activated in the cortex large numbers of cells across the cortical mantle begin to oscillate at a very low frequency laquo 1 Hz)

The cortical slow rhythm referred back to the thalamus via corticothalamic circuits intensifies the hyperpolarizing effect of the RTN spindle bursts on TC cell membranes When V m -75 mV the TC cells begin to generate their own intrinsic calcium currents which further increases hyperpolarization At V m -90 mV the RTN neurons stop firing spindle bursts The TC cells continue to fire low-threshold calcium spikes in patterns which are controlled by the cortical slow rhythm The interaction of these two oscillations generates the delta waves (1 to 4 Hz) which are associated with stage 2 NREMS

In a study of sleep rhythms using the cortical EEG Uchida Atsumi and Kojima found that the mean number of spindles required to induce delta wave activity (that is to induce Vm = -90 mY) is 478 plusmn 162 spindles (from 3 to 7 spindles)22 The mean number of spindles in a volley remains the same for a single individual over multiple trials

Based on the consensus scenario for generation of NREMS we can predict that a phosphene image generated as an epiphenomenon of a thalamic spindle

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 125

Table II Dara show rhe degree of correspondance berween rhe pulse panerns of rhalamic spindles based on intracellular research and rhe sparioremporal panerns of receding annuli phosphenes induced by rhe author using a rechnique of self-hypnosis

Receding annuli phosphenes Thalamic spindle bursrs

Mean number of signals 4 annuli 487 (plusmn 16) bursrs

Sparial exrension vs Thin band 1 - 3 seconds durarion of signal ( 05 -15 cm)

Periodicity of signals 5 seconds 3 - 10 seconds

Simultaneity in LGNs Yes Yes

Point of entry Peripheral VF Ventral amp lareral LGN

Trajecrory Bilareral concentric Unknown

Rare of flow Cons rant rare Unknown

Signal-ro-noise rario High High (shorr bursrs) (sharp brighr discrere)

Termination of sequence Mrer 4 signals Mrer 487 (plusmn 16) signals

will present the following characteristics (1) a high-definition burst-like signal (2) that recurs within 3 to 10 seconds (3) that follows a trajectory compatible with having entered the LGN from the RTN (4) that has a predictable mean for the individual subject and a range that falls somewhere between 2 to 7 annuli and (5) that the spindles will terminate automatically

The temporal patterns of receding annuli and thalamic spindle bursts are similar Table II illustrates the close match between the timing of receding annuli phosphenes and thalamic spindle bursts The most striking similarities are the mean number of signals required to induce termination (4 annuli versus 487 spindles) and the interval between signals (5 seconds for annuli versus 3shyto-lO seconds for spindle bursts) Neither alpha theta nor beta waves present this kind of stereotyped temporal pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 126

T he spatial features of receding annuli are functions of geniculate anatomy A spindle burst moving through the LGN to the cortex will acquire certain distinctive spatiotemporal characteristics because of the

unique curvilinear and laminar anatomy of the LGN A drawing of a macaque LGN based on a clay model constructed by Le Gros Clark23 is shown in Figure 3 The primate LGN is composed of six sheets of cells or laminae that fold over a central hylus In macaques the hylus rises steeply as it extends rostrocausally forming a high arch at the posterior pole in humans the hylus is much more shallow but the functional anatomy is thought to be essentially

23 24the same in both cases - The geometry of the arch forces each lamina to bend so as to constitute in effect one-half of a conical surface and each lamina with its hemi-conical shape contains visual relay cells representing the contralatshyeral half of the visual field (VF) Operating as a pair the complementary hemishycones of the right and left LGN form the functional equivalent of a single conical surface which represents the entire VE This conical geometry of the paired LGNs means a burst of otherwise formless excitation will acquire a distinctive shape as it propagates through the laminae of the LGN Imagine a horizontal section moving along the surface of a cone from base to apex that moving section forms an annulus that shrinks in diameter as it approaches the apex but retains its annular symmetry throughout its trajectory

Figure 3 also includes drawings that show how Connolly and Van Essen24

converted the 3-dimensional structure of lamina 6 the largest and most dorsal layer into a 2-dimensional map Connolly and Van Essen used data obtained by Malpelli and Baker25 to superimpose a grid that specifies the areas in lamina 6 that contain TC cells representing various degrees of isoeccentricity in the VE We will use this map at a later point to show how the movement of a spindle wave through a pair of LGNs correlates with what appears in the VE

The location of the RTN relative to the LGN is also shown in Figure 3 The RTN spindle pacemaker is a thin sheath of GABAnergic inhibitory cells that extends along the surface of the whole posterior ventral thalamus not just the LGN This extension brings the RTN into close proximity with the portion of the LGN (lateral wing) that protrudes out from the main body of the thalamus Some of RTN wraps around and beneath the ventral edges of the LGN26 The RTN comes closest to the LGN in two areas along the ventral edges of the longest laminae (lamina 6 and 1) and along the edge of the lateral

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 127

DORSAL POLE DORSALPOIEA B

L1 L4 L3 L

DORSAL POlE DORSAL POIE (FOVEA)

G LATERAL WING

25

DORSAL POL (FOVEA)

10 _DIAL

20 WING

~

wing These areas contain TC cells that represent the far periphery of the VE If a spindle burst enters the LGN at locations where laminae are in closest proximity to the RTN-along the ventral edges-then the discharge of TC cells will begin in the most ventral portions of the laminae the regions that represent the far periphery of the VE This matches the phosphene sequence observed by the author

Our hypothesis about how this proximity between RTN and LGN affects the trajectory of spindle waves is illustrated in Figure 4 We propose that it is not possible for the author to observe a thin annulus of phosphene sweeping in from all 3600 of the peripheral VF unless spindle bursts exhibit the following

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 128

Figure 3 [facing page Drawings of primate geniculate anatomy and functional anatomy relevant to the generation ofphosphenes (A) Anterior view ofa macaque monkey LGN based on a clay model reconstruction by Le Gros Clark 23 (B) Posterior view ofthe same model showing 6 laminae folded over a central hylus to form lateral and medial wings with the hylus arching steeply upward near the posterior pole to shape the laminae into layers of hollow half-cones nested together Note that the lateral wing of the LGN is slightly larger than the medial wing so that in situ the lateral wing protrudes out from the main body of the thalamus creating a small knob visible during dissection 26 (C) Schematic drawing of an oblique section through median axis (also adapted from Le Gros Clark13 showing how the laminae fuse together at the anterior pole The afferent ganglion cell axons that form the optic tract (OT) penetrate through the anterior surface to reach their target relay cells in the laminae (D) Drawing of the most dorsal lamina-layer 6--separated from the rest of the LGN The geometric shape is a hollow half-cone so that right and left LGNs placed back-to-back form in effect a single cone Note also the position ofthe RTN shown here as a striped bar relative to lamina 6 The position of the striped bar shows that the RTN makes direct contact with lamina 6 at the edge ofthe lateral wing and also along the ventral edges (E - F) Schematic drawings adapted from Connolly and Van Essen24 that show how a 3-dimensional lamina-lamina 6--can be transformed into a 2-dimensional triangular figure lamina 6 is removed and its wings unfolded (E) creating a slightly asymmetric triangular figure (F) which is adjusted to an oblong shape (G) in order to superimshypose a grid matrix with minimal distortion The grid plots locations of TC cells that represent various isoelevations and isoazimuths in the VF locations derived from the experimental observations published by Malpeli and Baker 25 Note the relatively large amounts of laminar surface allocated to central vision (0 0

- 30 0) as compared

to peripheral vision (30 0 - 80 0)

characteristics (1) Spindle bursts must move simultaneously through both geniculate nuclei This pattern of movement is consistent with anatomical studies in primates that found axonal projections linking the right and left RTNs27-28 and with experimental studies in cats that found spindles appearing simultaneously in both right and left thalami 29 (2) Spindle waves must enter the ventral edges of the LGN first and move ventrodorsally in a highly coherent pattern-moving in effect as a standing wave This pattern of movement is consistent with in vitro experiments using sagittal slices from a ferret LGN where spindle waves originated spontaneously at the edge of a slice in an area which contains cells that represent peripheral vision then propagated toward that area of the slice containing cells that represent central vision in the ferret 3o

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 129

VF

PG BIlateral receptive lleJd of PVN YI(j Inward dmKooflality Adapled

0-- from Mortgr at at (1987)

V1

ibull t bull

RTN t t t t t t 1middot3 SECOlO BURSTS OF 7middot14 HZ SPiKES RECURRNG EVERY 3 10 SECONDS

To our knowledge the LGN is the only anatomical structure in the visual system that has the capacity of passively forcing a wave of excitation to flow across a conical surface thereby generating the sensation of a phosphene annulus that retains its symmetry as it shrinks in diameter The retina has a circular anatomy but it is not likely that the mechanical deformation of the retina would produce a wave that began simultaneously in all 3600 of the retinal rim nor that the symmetry of annular wave would be preserved as it flows inward toward the foveal region

The hypothesis presented here-that there is a structure in the visual system that imprints a conical shape on standing waves that move through it-explains

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 130

Figure 4 facing page Schematic drawing of contemporaneous events in selected regions of the visual processing hierarchy (A) The left and right RTNs fire spindle bursts simultaneously (B) The bursts pass through the right and left geniculate laminae as standing waves of depolarization entering from the ventral edges and moving ventrodorsally in parallel In order for the phosphene annulus to appear to be flowing at a constant rate the spindle wave flowing through the LCN must expand in width as it ascends ventrodorsally so that by the time the fill-in disk appears-when the center 30deg of the VF is covered by the phosphene annulus-the spindle wave must have expanded enough to activate relay cells in the most dorsal 50 of lamina 6 (C) Signals representing two complementary hemi-annuli are kept separate in the primary visual cortices (area VI) (D) Signals representing the two hemi-annuli are integrated into signals of a single annulus when they reach area PC in the posterior parietal cortex where the receptive fields of single parietal visual neurons have the capacity to register bilateral signals that exhibit opponent vector movement (that is signals converging from opposite directions along the central axes-as if an object were moving away from the viewer)46 Neurons in area PC also integrate wavelength (color) signals from the extrastriate visual pathway with signals about brightness motion and depth from the parietal visual pathway to compose a representation of an object in space-in this case of an annulus that appears to recede 32

the authors experience during MRI when he observed a continuous succession of receding annuli every 2 seconds in this view the energy of the electroshymagnetic bombardment when released during precessional relaxation flows through the geniculate laminae in the same way that the RTN spindle bursts do that is as a standing wave and thus the visual epiphenomenon is the same in both cases if the subject keeps the eyes focused straight ahead and the attention fixated In a study of phosphenes evoked by electricity in conjunction with hallucinogenic drugs Knoll Kugler Hofer and Lawder found that each subject sees specific kinds of phosphene at different frequencies and that these frequency-specific images are stable enough to be reproduced after six months31

They conclude that the tunability of the electrical stimulation frequenshycies within the EEG range to various definable phosphenes requires the existence of a resonance system One mechanism contributing to that resonance system may be the functional anatomy of the LGN

The colors of receding annuli as functions of geniculate laminar anatomy The colors of receding annuli phosphenes are consistent with the patterns of discharge spindle waves can be expected to stimulate as they move through

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 131

geniculate laminae As shown in Figure 5 the six laminae differ (1) in the types of wavelength signals relayed (2) in physical size and (3) in the area of the VF represented 24-25 Only 4 out of 6 laminae Cparvocellular layers 3shy6) contain TC cells that relay wavelength signals the other 2 laminae (magnocellular layers 1 and 2) do not encode wavelength Among parvocelshylular laminae only lamina 6 the longest and most dorsal layer contains TC cells that can represent the far periphery of the VF (from 800 to 50deg of isoeccenshytdeity) therefore when the spindle wave enters the peripheral VF only those wavelengths relayed by lamina 6 will participate in composing a cortical lightness record (See Zeki)32

I n lamina 6 ganglion cell axons arriving from the retina carry two kinds of wavelength signals (1) center-ON signals from medium-wavelength cones (M-cone center-ON) and long-wavelength cones (L-cone centershy

ON)33-35 Using the cone spectral sensitivity curves (adapted from Marks et al 36) we average the wavelengths that elicit maximal responses for M-cones (535 nanometers) and L-cones (520 nm) which yields a mean wavelength value of 550 nm In humans this wavelength generates a sensation of green or yellowshygreen the sensation observed by the author

As the spindle burst moves ventrodorsally it reaches the dorsal areas in the geniculate laminae which contain TC cells representing the central 0deg to 20deg of isoeccentrieity in the VE All 4 parvocellular laminae have TC cells which are potentially capable of representing this central region of vision but the authors observation that the color of the filling-in disk changed from green to blue implies that in the early years of phosphene induction the spindle wave must have remained close to the surface of the LGN stimulating only laminae 5 and 6 which generates a sensation of yellow-green When the fill-in disk was observed to change color from green to blue the spindle wave must have been rechanneled so that it began to penetrate below laminae 5 and 6 and to activate laminae 3 and 4 the only laminae that relay blue-sensitive signals (Sshycone center-ON signals)3 In light of the authors MRI experience it seems likely that a spindle wave requires a minimum of 2 seconds to reach the blueshysensitive cells of laminae 4 therefore during MRI when the receding annuli disappeared after 2 seconds half the normal duration the fill-disk had a green color even though it had long since change to blue in other induction settings with a 4-second trajectory

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 132

A REPRESENTATION OF THE VISUAL FIELD IN EACH LAMINA

orooqUtftc O-u OCIJ1SALfIOLI (I01flAj

0

10

20

30

40 n50 Of

60

70

20 loO 1Mgr_ II~ o UIpoundAS65 mn1MY-o actlvncL ~~~r

Jll-COMcetlImiddot~

II LAYERSU 3 GatQYancetl~ (1) ucon ceom-oyenF (2)l~cen()FF 3) ~ cenloH

II~ cng1loqctWIIIfNla

iICINe -- (t81Otdb1t1d~OH (2)~

80

B CONE SPECTRAL SENSITIVITY CURVES

S-COHS

WAVIlLllNG1llS OF UGHT IH NANOMllTERS (NM)

Figure 5 Phosphene color as a function of ganglion cell distribution in parvocellular laminae (Aj Schematic drawing ofthe proportion ofthe VF represented in each laminae The proportions shown here are based on the work of Connolly and Van Essen24 The

far periphery of vision (50 0 to 80 0 of isoeccentricity) is represented in only two laminae-laminae 1 and 6-and of these two only lamina 6 is a parvocelLular lamina capable ofencoding wavelength signals Therefore only those wavelengths relayed by lamina 6 will participate in forming a cortical lighmess record for the far periphery of the VP (B) Cone spectral sensitivity curves (adapted from Marks et al)36 Using these cone sensitivity curves we can estimate the sensation stimulated by a spindle wave moving through lamina 6 by averaging the wavelengths that elicit maximal responses for M-cones (535 nanomeshyters) and L-cones (520 nm) which yields a mean wavelength value of550 nm In humans this generates a sensation of green or yellow-green the sensation observed by the author when the receding annulus enters at the far periphery of the VP For a calculation of the cortical lightness record when a spindle wave moves through 20deg to 0deg ofthe VF stimulating all 4 parvocelfular laminae see the text and Figure 6

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 133

Once the spindle wave penetrates to laminae 3 and 4 it may activate all 4 parvocellular laminae stimulating TC cells to send contradictory wavelength signals for the same retinotopic location the signals sent from laminae 4 and 3 will encode blue light (S-cone center-ON plus M-cone center-OFF and Lshycone center-OFF) while the signals sent from laminae 5 and 6 encode yellowshygreen light (M-cone center-ON plus L-cone center-ON) This kind of contrashydiction does not occur in normal retina-based perception where light energy striking the retina is structured by the retinas center-surround and colorshyopponent organization to encode only one set of wavelength signals for each spatial locus 32 In Figure 6 we estimate the cortical lightness record that results when contradictory wavelength signals compete to be represented in consciousshyness Our calculations suggest that the outcome will be a mean wavelength which in humans elicits a dark blue or violet sensation

PART II AMORPHOUS PHOSPHENES amp THALAMIC DELTA ACTMTY

M echanisms controlling the transition from spindle bursts to delta activity In the consensus scenario for the generation of NREMS16-20 we noted that the RTN shifts to firing spindle bursts

when polarization of thalamic cell membranes drops to V m = - 60 mV At the same time cortical cells begin oscillating with a synchronous slow rhythm laquo 1 Hz) Both processes further decrease the Vm of TC cell membranes When Vm = - 75 mY TC cells begin to generate their own intrinsic calcium currents which also decreases V m At V m = - 90 mV RTN neurons stop firing spindle bursts At the same time the TC cells begin firing low-threshold calcium spikes in alternation with after-hyperpolarizations (LTS-AHP) Because sensory relay neurons in the LGN are not linked to one another by locally projecting axons the firing of one TC cell does not excite its neighbor However a lack of local connectivity does not mean that TC cells occupying the same laminae release their AHP-LTS calcium spikes in a random distribshyution rather spikes are released simultaneously by groups of cells in synchrony with the advent of the cortical slow wave In effect the distribution of LTSshyAHP spikes firing in the LGN is determined by the spatial propagation of the cortical slow wave Thus the delta wave (1 to 4 Hz) activity detected by cortical EEG during NREMS is a product of the interaction between the AHP-LTS calcium spikes released by TC cells and the cortical slow rhythm

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 134

CORTICAL PROCESSING OF CONTRADICTORY

WAVELENGTH SIGNALS

KEY _ Cells firing

cJ Cononol firing

Assume that as a spind6e wave moves through the LGNlt fires simultaneously aU the TC cells that represent a particular reUnoshytopic locus (x y) in each of the six laminae As a result cortical cells engaged In the higher level processing of visual signals will receive more wavelength signals representing retina locus (x y) than are generated by normal perception laquo and some of these afferent wavelength signals may contradict other signals arriving simultaneously

CORTICAL LIGHTNESS RECORD SlgnalSell

Intemal contradictions not congruent wilt pre

SmiddotON eristing neuron neta

s bullbull M-ON LmiddotON

3 bullbull M-OFF + L-OFF

a-ON 12

ROD-ON

No Internal eonlradlemiddot

--------1I =~8b~~~~~~~t signals

3+4

~ --OFF Excludes 6 Of 7 $J9n18

1+2 B-ON I

IWmiddotHmiddotI Signal Sell

1111111 No Intern1 conlrfldlcshy lion

Exelvdta 4 out of 7 efshy

bullbullbull bullbullbull ferant signals

No Intern1 contradic_ tionnee S-ON BshyOH and ROO-ON can all be coacllve at low lImlnance levels nef Ihe rod-eone break

ExchJde$ only 2 Ollt of 7 afferent signals

Figure 6 Selection of competing wavelength signals based on neuronal group selection This thought experiment is based on Edelman sconcept ofneuronal group selection 73 We assume that all possible combinations ofsignals will form sets and that all signal-sets will compete to make the most efficient match with pre-existing neuromd networks that have been forged over years ofnorma reti1U1-based perception We also assume that pre-existing neural networks are most likely to expedite those sets that satisfY 2 criteriI (J) the signals in a set do not contradict each other and (2) fower signals are excluded than in the other sets that satisfY the first criterion In our analysis Set 4 wins the competition because it does not contain internal contradictions and excludes fower signals (2 out of 7) than Set 3 excludes (4 out of7) It is not an internal contradiction that Set 4 contains both rods and cone Signtlls in normal retina-based perception when luminance levels approach the rod-cone break S-cone center-ON receptors send signas as do rod receptors and there is even evidence that rod activity may actually drive S-cone activity even after luminance levels foIl below the rod-cone break74 To calculate the cortical lightness record for Set 4 we average the wavelength that elicits maximal responses foom rods (511 nm) and for Sshycones (430 nm) which yields a mean wavelength of 470 nm which in humans results in a dark-blue or violet sensation

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 135

The cortical slow rhythm is an example of a generic pattern of neuronal excitashytion that occurs in large networks of neurons linked by local projections A recent experiment by Maeda Robinson and Kwana38 shows that networks of locally-connected neurons spontaneously generate periodic synchronized bursts of calcium transients that propagate across the network in an expanding spatial wave a pattern that represents a stable mode of firing towards which these neuronal networks relax following perturbations for example by electronic stimulation or by drugs Understanding the characteristics of these waves is an important prerequisite to understanding the mechanisms that produce the amorphous phosphene images as a visual epiphenomenon

To study the spontaneous periodic synchronized bursts the researchers prepared cultures of dissociated cortical neurons and allowed them to mature for several days in vitro (DIV) After 3 to 4 DIV when concenshy

trations of extracellular magnesium were low electrodes began to detect spontaneous synchronized bursts of low frequency calcium transients (between 01 and 1 Hz) that originated in different locations on the sheet every 10 to 20 seconds and spread across the sheet of cells at a relatively slow speed averaging 50 mmsecond The researchers could not predict where a wave would originate or where it would expand rather the initiation and expansion of waves was generated by spatial and temporal summation of a continuous random background of synaptic inputs including miniature spontaneous synaptic events but the pattern was not random since waves propagated sequentially from electrode to electrode as each local group of neurons charges up its neighboring nontefractory areas rather than in a random sequence of regions38

The excitability of the cells in the sheet determines the probability first that there will be a synchronous burst and second that it will spread in a particshyular direction Cells become more excitable as the cultures mature which means the refractory intervals between successive bursts were much shorter in mature cultures (gt 30 DIV) than in early cultures laquo 7 DIV) Some cells became so insensitive to inhibition that they continued to fire bursts even when extracellular concentrations of magnesium were relatively high Finally there were refractory periods of 5 to 10 seconds during which no bursts occurred even when an electrical stimulus was applied This refractory interval for cultured networks is slightly longer than the refractory interval observed of the cortical slow wave in vivo which 25 to 4 seconds 18- 19

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 136

Based on the observations about cortical slow waves we can predict that phosphenes generated as epiphenomena of delta wave activity will present the following signal characteristics (1) signals that appear at unpredictable locations in the VF (2) signals that expand and diverge asymmetrically following unpredictable trajectories which may encompass large areas of the VF (3) signals that move relatively slowly (50 mmsec) (4) signals that recur with a period of 2 to 4 seconds reflecting entrainment by the cortical slow wave (5) signals that do not terminate automatically after a predictable number of cycles

The spatial patterns of phosphene mists and thalamic delta waves are similar The spatiotemporal characteristics of amorphous phosphenes match the pattern of wave propagation associated with periodic spontashy

neous synchronized bursts in large neuron networks the amorphous phosphenes enter the visual field at unpredictable locations expand and diverge asymmetrically with a slow steady rate of flow follow trajectories that are unpredictable and exhibit a refractory interval The amorphous mists do appear to have a periodicity although the author is unable to sustain the vision while also counting the seconds therefore he is unable to determine if it compares to the period of the cortical slow wave (25 to 4 seconds) but his impression is that it feels roughly the same as as with receding annuli which recur at 5 seconds Also the refractory interval feels as if it decreases as the induction session is extended These similarities suggest that the amorphous phosphenes are generated by stage 2 NREMS delta wave activity which is an activity governed by the reverberation of the cortical slow wave in thalamoshycorticothalamic circuits The cortical slow wave is referred to the LGN where it modulates the firing of visual relay cells in the laminae and since relay cells do not have local dendritic connections the expansion of a wave of depolarshyizations moving from one relay cell to the next across in the laminar surface will mirror at least in part the expansion of the cortical wave that is spreading contemporaneously through locally-connected cortical cells

PART III RETENTION OF CONSCIOUSNESS

In a normal transition to NREMS the volley of synchronous spindle bursts that marks the onset of stage 2 NREMS overwhelms the normal firing pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 137

of thalamocortical cells preventing their relay of afferent sensory signals and inducing a loss of consciousness21 But the loss of consciousness cannot be timed precisely using cortical EEG the thalamus is too remote for the onset of spindling to be reliably detected by scalp electrodes39 In experiments with cats where electrodes could be implanted in the thalamus researchers found that spindling often reached peak levels of activity in the thalamus-a level of activity consonant with stage 2 NREMS-at a time when the cortical EEG was still showing intermittent desynchronizations a pattern characteristic of the drowsy stage 1 transition not a fully-established stage 2 NREMS episode4o

In other words there is a short period of time in which the synchronous rhythms of stage 2 NREMS are installed in the thalamus but not in the cortex where cortical neurons continue to depolarize in response to afferent sensory signals

T his finding suggests a possible explanation for the authors ability to retain consciousness while spindle bursts are sweeping through the LGN if he is able to extend the duration of this time lag between

the onset of spindling in the thalamus and spindling in the cortex if he is able to stimulate the visual cortices in such a way that they continue to depolarize then he may be able to keep on processing visual signals-to remain visually aware-even after the non-visual thalamus and non-visual cortex become entrained by synchronous sleep rhythms The authors induction technique includes several behaviors which are known to enhance the responsiveness of visual neurons-eye movements attentive fixation and an attitude of expectancy

Effects of eye movements and attention on the LGN Sustained convergence causes periorbital proprioceptors to send excitatory feedback directly to the LGN41 Also convergence further enhances the excitability of geniculate cells by stimulating the superior collicus (SC) which sends its own excitatory signals to the LGN42-43 These signals from the SC are known to selectively enhance the excitability of visual relay cells that represent the periphery of vision44 We know in the authors case that the SC is being stimulated because he is able to keep on fixating an ability which would normally be lost during the transishytion to NREMS45 The ability to fixate can be retained however if the SC is stimulated (even if stimulated during NREMS)46

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 138

Effects of eye movement attention and expectancy on the primary visual cortex The PET study of mental imagery by Kosslyn et al 3 showed that even a baseline resting state of relaxed immobile expectancy can generate signifishycant increases in neuronal activity in the primary visual cortices Further increases can be induced by sustained eye movements

A sustained convergence will release a stream of ponto-geniculo-occipital (PGO) waves These PGO waves called eye movement potentials or EMPs last only as long as the eye movement1747 whereas the PGO waves associated with rapid-eye-movement sleep (REMS) fire continually for the duration of the REMS episode Both REMS-related PGO waves and EMPs have the same desynchronizing effect on the visual pathways they move through the LGN depolarizing the thalamocortical cells which relay the signals to cortical neurons The responsivity of neurons in the primary visual cortices is enhanced by the stimulation of PGO waves 1747-49 If the passage of EMPs causes the genicushylate relay cells and their cortical targets to depolarize regularly then a volley of 4 spindle bursts moving through the same pathways will register as just another series of depolarizations in effect the spindle bursts are processed by the visual system as if they were sensory signals sent from the retina rather than an event stimulated by endogenous mechanisms

T he impact of eye movements and ftxation on the parietal visual cortex Convergence and attentive fixation will also enhance the responsiveness of light-sensitive parietal visual neurons (PVNs) in area PG of the

posterior parietal cortex 50 In experiments where monkeys are trained to fix their attention on a screen-and to keep on fixating even if no targets appearshythe excitability of these light-sensitive PVNs increases by as much as 350 51

52-53Responsiveness is also facilitated by the angle of gaze Also area PG is the first region in the visual pathways containing individual neurons with the capacity to respond to large bilateral stimuli moving in opposite directions along the central meridians of vision (opponent vector motion) 853-55 Facilitation of PVNs in area PG has the effect of sensitizing the subject to bilateral opponent vector motion and this is especially true if the movement appears in the periphery of the VE 8

Intracortical ampliftcation and feedback to the LGN When PGO waves and signals from the SC arrive in the primary visual cortex they may be relatively weak however weak signals can be amplified by reverberating in large networks

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 139

of cortical cells linked by local projection 56 There are nine times as many excitatory links among cortical cells as there are projections from the visual cortex to the LGN an imbalance which suggests leads Suarez Koch and Douglas to propose that geniculate input provides only a minor fraction of the excitatory input the majority originating in neighboring and recurrently connected cortical cells57 If the excitabiliry of cortical neurons is slightly higher than normal then this process of amplification may continue even after the LGN signals that initiated the reverberation are no longer being transmitted by the LGN ( a hysteretic mode of operation) 57

Feedback from hyperexcited cortical neurons will stream back to the LGN via corticogeniculate projections which outnumber geniculocortical projections ten-to-one One effect of this feedback is that the LGN is

able to absorb large amounts of information flowing back from the cortex 58

As signals reverberate back and forth in thalamocorticothalamic circuits a matching process takes place those geniculate relay cells that fire in patterns consistent with the firing patterns of active cortical cells will have their responshysivity enhanced while those geniculate cells that fire in patterns not consistent with cortical cells will be suppressed 59

Preservation of consciousness by selective facilitation of the visual pathways By combining all of the facilitatory effects produced by the authors eye movements and attentive fixation-(l) stimulation of the LGN by feedback from periorbital proprioception both directly and indirectly via the SC (2) the release of PGO waves (EMPs) that facilitate neurons in the LGN and primary visual cortex as they pass (3) the facilitation of the primary visual cortex by a state of relaxed immobile expectancy (4) attentive fixation and angle of gaze that facilitate PVNs in area PG (5) intracortical amplification of signals received from the LGN and (6) corticogeniculate feedback that stimulates the LGN-we delineate a circuit of enhanced excitability that extends from the LGN through the post-geniculate visual heirarchy to area PG where signals are integrated into representations of objects

The hyperexcitability of neurons all along the post-geniculate visual pathways creates conditions in the visual cortices which are similar to those present during EEG-desynchronized states of waking and REMS Therefore neurons in the visual pathways are too excitable to be entrained by synchronous bursting

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 140

patterns when spindle waves move through them instead the spindle bursts stimulate visual neurons to depolarize and then recover as happens in response to afferent sensory signals during waking states It is important to note that for this to occur none of the constituent neuron assemblies is required to perform an abnormal operation the abnormality is a function of the authors intent to activate contemporaneously neuron assemblies that would not normally be co-activated

PART IV HYPNOTIC ANALGESIA

Manipulation of spatial attention as a method for alleviating pain sensations In a theoretical article on the neurophysiology of hypnosis Crawford and Gruzelier60 propose that variations in hypnotizability are function of variability in the efficiency of the frontolimbic (anterior) attentional system in humans high-hypnotizables are better able to sustain focused attention on a task and to ignore extraneous stimuli than are low-hypnotizables

I na related empirical study that compares the use of attention by subjects with high versus low hypnotizability Crawford Brown and Moon61 report that highly hypnotizable persons continue to show physiological reactivity

while cognitively not perceiving the painful stimuli Through disattentional processes they can dissociate themselves from the awareness of pain The authors phosphene induction behaviors-and the cutaneous analgesia he experishyences-appear to involve the same kind of behaviors that is a mobilization of frontolimbic attention used to withdraw attention from external stimuli and to concentrate it on internally-generated phosphene images This suggests the hypothesis that the mechanisms that generate phosphenes might also produce hypnotic analgesia There are several ways that visual signals and pain signals might interact to produce this analgesia

Competition between pain and vision signals for limbic registration The fully-developed sensation of pain requires integration of rwo kinds of informashytion Signals that encode the location and intensity of a noxious stimulus (nociceptive signals) are relayed via the thalamus to the somatosensory cortices which registers only the sensory-discriminative aspects of pain perception62 before reaching consciousness the nociceptive signals must be sent to the limbic

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 141

system where they are linked with signals from long-term memory that encode the affective significance the stimulus has acquired for that individual Studies of brain metabolism show this linking of somatosensory information with limbic associations takes place in the anterior cingulate (CG) and anterior insula62-64

PET studies also show that the anterior CG is activated when subjects shift their spatial attention in response to expectations as to where

66stimuli will next appear65- This is precisely what takes place during the state of immobile expectancy that induces phosphenes Since visual signals and nociceptive signals both require limbic enhancement which is only possible if they get access to the anterior CG there might be conditions in which the two types of afferent sensory signals have to compete for that access In a theoretical article on the mechanisms of attention Posner and Rothbart67

propose that visual signals can interfere with nociceptive signals by blocking access to the anterior CG As behavioral evidence they cite studies showing that when young infants make distress calls they can be distracted by the presentation of a new visual stimulus We have shown the evidence of such control at about three months Orienting to visual events can be employed to quiet or calm negative vocalizations However the distress appears to be maintained and reappears when the infants attention to the stimulus is reduced Caregivers also report the use or visual orienting to block overt manifestations of distress at about this age 67

The effects of disattention on the somatosensory cortices If there is a competition between visual signals and nociceptive signals for access to the anterior CG it is likely that the competition will be affected by the relative volume of signals received A recent study suggests that focusing attention on internally-generated visual stimuli may reduce the number of nociceptive signals relayed by the somatosensory cortices Drevets Burton Videen Snyder Simpson and Raichle68 have shown that the mere anticipation of a touch at a specific cutaneous site increases the flow of blood to those cortical somatosenshysory neurons that are linked with that site where touch is expected and decreases the flow of blood to neurons linked with sites where touch is not expected In this experiment the researchers designated touch as the behaviorally significant sensory stimulus but their findings suggest that the outcome could be reversed if the instructions were reversed if subjects were

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page J42

instructed to direct attention away from a cutaneous site where a noxious stimulus was being applied if they were instructed to relax close their eyes and concentrate on the play of phosphenes in the visual field as the behaviorally significant sensory stimulus then it would be reasonable to expect that the flow of blood would decrease to the somatosensory neurons linked with the cutaneous stimulus and that the flow of blood would increase to the visual cortices The decrease in blood flow to somatosensory neurons implies less neuronal activity which implies that fewer signals are being sent forward to the anterior CG than would have been sent if instead the subject were treating the touch as the behaviorally significant sensory stimulus If fewer pain signals arrive at the anterior it is reasonable to infer that the conscious experience of pain will be muted by the diversion of attention to internal visual stimuli

Differential impact of sleep rhythms in the visual and nonvisual thalamus There is another mechanism that might also contribute to the analgesic effect of inducing sleep rhythms PET studies show that

the thalamus is involved in the relay of nociceptive signals to the cortex63 although some confusion remains about which kinds of signals are relayed by which subregions in the thalamus62 One thalamic site clearly identified by anatomical studies as a relay for nociceptive signals is the ventroposterior lateral nucleus (VPL)69 If synchronous sleep rhythms are active in the thalamus we can reasonably expect that the VPL will itself be entrained by synchronous oscillations and that it will relay the sleep rhythms to somatosensory cortices Relay neurons in the VPL are not stimulated by feedback from eye movements and fixation as are relay neurons in the LGN which suggests that sleep rhythms may impede the relay of nociceptive signals via the VPL but not the relay of visual signals via the LGN

Brain waves associated with anesthesia and NREMS The hypothesis presented here-that consciousness can be preserved despite the presence of NREMS activity-is consistent with a recent report that the kinds of fast brain waves which are normally associated with conscious states are also present during NREMS and anesthesia two states which were thought to involve minimal brain activityJo Another recent study found that there is a close resemblance between the slow brain waves that appear during NREMS and those that appear during certain types of anesthesia71

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 143

bull bull bull

CONCLUSION

In this paper we have presented evidence supporting the hypothesis that phosphene images can be generated as an epiphenomena of thalamic spindle bursts and delta wave activity normally associated with NREMS The prereqshyuisites for inducing these sleep rhythm phosphenes are relaxed immobile expectancy sustained convergence and attentive fixation of an undifferentiated visual field Our hypothesis provides a necessary and sufficient explanation for the authors induction of phosphenes and perhaps also for the generation of phosphenes reported to appear spontaneously during the drowsy transition to sleep (hypnagogic states) during sensory deprivation or during certain kinds of prayer or meditation all of which involve a similar state of relaxed immobile expectancyJ2

CORRESPONDENCE Philip T Nicholson bull 52 Norfolk Road bull Chestnut Hill MA 02167

REFERENCES amp NOTES

1 M 1 Posner Modulation by Instruction Nature 373 (1995) pp 198-199 2 J Reissenweber E David amp M pfotenhauer Investigations of Psychological Aspects of

the Perception of Magnetophosphenes and Electrophosphenes Biomedizinische Tecknik 373 (1992) pp 42-45

3 S M Kosslyn W L Thompson 1 J Kim amp N M Alpert Topographical Representations of Mental Images in Primary Visual Cortex Nature 378 (I995) pp 496-498

4 P E Roland amp B Gulyas Visual Memory Visual Imagery and Visual Recognition of Large Field Patterns by the Human Brain Functional Anatomy by Positron Emission Tomography Cerebral Cortex 51 (1995) pp 79-93

5 H Benson The Relaxation Response (Morrow New York NY 1975) 6 ] H Schultz amp W Luthe Autogenic Training a Physiological Approach to Psychotherapy

(Grune amp Stratton New York NY 1969) 7 E Jacobson Progressive Relaxation (University of Chicago Press Chicago IL 1938) 8 M A Steinmetz BC Motter C] DuffY amp V B Mountcastle Functional Properties

of Parietal Visual Neurons Radial Organization of Directionalities Within the Visual Field Journal ofNeuroscience 71 (1987) pp 177-191

9 R R Edelman Magnetic Resonance Imaging of the Nervous System Discussions in Neuroscience 71 Elsevier Science Amsterdam (I990) also J H Newhouse amp ] I Wiener Understanding MRI 1st Ed (Little Brown Boston MA 1991)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 144

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

Table II Dara show rhe degree of correspondance berween rhe pulse panerns of rhalamic spindles based on intracellular research and rhe sparioremporal panerns of receding annuli phosphenes induced by rhe author using a rechnique of self-hypnosis

Receding annuli phosphenes Thalamic spindle bursrs

Mean number of signals 4 annuli 487 (plusmn 16) bursrs

Sparial exrension vs Thin band 1 - 3 seconds durarion of signal ( 05 -15 cm)

Periodicity of signals 5 seconds 3 - 10 seconds

Simultaneity in LGNs Yes Yes

Point of entry Peripheral VF Ventral amp lareral LGN

Trajecrory Bilareral concentric Unknown

Rare of flow Cons rant rare Unknown

Signal-ro-noise rario High High (shorr bursrs) (sharp brighr discrere)

Termination of sequence Mrer 4 signals Mrer 487 (plusmn 16) signals

will present the following characteristics (1) a high-definition burst-like signal (2) that recurs within 3 to 10 seconds (3) that follows a trajectory compatible with having entered the LGN from the RTN (4) that has a predictable mean for the individual subject and a range that falls somewhere between 2 to 7 annuli and (5) that the spindles will terminate automatically

The temporal patterns of receding annuli and thalamic spindle bursts are similar Table II illustrates the close match between the timing of receding annuli phosphenes and thalamic spindle bursts The most striking similarities are the mean number of signals required to induce termination (4 annuli versus 487 spindles) and the interval between signals (5 seconds for annuli versus 3shyto-lO seconds for spindle bursts) Neither alpha theta nor beta waves present this kind of stereotyped temporal pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 126

T he spatial features of receding annuli are functions of geniculate anatomy A spindle burst moving through the LGN to the cortex will acquire certain distinctive spatiotemporal characteristics because of the

unique curvilinear and laminar anatomy of the LGN A drawing of a macaque LGN based on a clay model constructed by Le Gros Clark23 is shown in Figure 3 The primate LGN is composed of six sheets of cells or laminae that fold over a central hylus In macaques the hylus rises steeply as it extends rostrocausally forming a high arch at the posterior pole in humans the hylus is much more shallow but the functional anatomy is thought to be essentially

23 24the same in both cases - The geometry of the arch forces each lamina to bend so as to constitute in effect one-half of a conical surface and each lamina with its hemi-conical shape contains visual relay cells representing the contralatshyeral half of the visual field (VF) Operating as a pair the complementary hemishycones of the right and left LGN form the functional equivalent of a single conical surface which represents the entire VE This conical geometry of the paired LGNs means a burst of otherwise formless excitation will acquire a distinctive shape as it propagates through the laminae of the LGN Imagine a horizontal section moving along the surface of a cone from base to apex that moving section forms an annulus that shrinks in diameter as it approaches the apex but retains its annular symmetry throughout its trajectory

Figure 3 also includes drawings that show how Connolly and Van Essen24

converted the 3-dimensional structure of lamina 6 the largest and most dorsal layer into a 2-dimensional map Connolly and Van Essen used data obtained by Malpelli and Baker25 to superimpose a grid that specifies the areas in lamina 6 that contain TC cells representing various degrees of isoeccentricity in the VE We will use this map at a later point to show how the movement of a spindle wave through a pair of LGNs correlates with what appears in the VE

The location of the RTN relative to the LGN is also shown in Figure 3 The RTN spindle pacemaker is a thin sheath of GABAnergic inhibitory cells that extends along the surface of the whole posterior ventral thalamus not just the LGN This extension brings the RTN into close proximity with the portion of the LGN (lateral wing) that protrudes out from the main body of the thalamus Some of RTN wraps around and beneath the ventral edges of the LGN26 The RTN comes closest to the LGN in two areas along the ventral edges of the longest laminae (lamina 6 and 1) and along the edge of the lateral

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 127

DORSAL POLE DORSALPOIEA B

L1 L4 L3 L

DORSAL POlE DORSAL POIE (FOVEA)

G LATERAL WING

25

DORSAL POL (FOVEA)

10 _DIAL

20 WING

~

wing These areas contain TC cells that represent the far periphery of the VE If a spindle burst enters the LGN at locations where laminae are in closest proximity to the RTN-along the ventral edges-then the discharge of TC cells will begin in the most ventral portions of the laminae the regions that represent the far periphery of the VE This matches the phosphene sequence observed by the author

Our hypothesis about how this proximity between RTN and LGN affects the trajectory of spindle waves is illustrated in Figure 4 We propose that it is not possible for the author to observe a thin annulus of phosphene sweeping in from all 3600 of the peripheral VF unless spindle bursts exhibit the following

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 128

Figure 3 [facing page Drawings of primate geniculate anatomy and functional anatomy relevant to the generation ofphosphenes (A) Anterior view ofa macaque monkey LGN based on a clay model reconstruction by Le Gros Clark 23 (B) Posterior view ofthe same model showing 6 laminae folded over a central hylus to form lateral and medial wings with the hylus arching steeply upward near the posterior pole to shape the laminae into layers of hollow half-cones nested together Note that the lateral wing of the LGN is slightly larger than the medial wing so that in situ the lateral wing protrudes out from the main body of the thalamus creating a small knob visible during dissection 26 (C) Schematic drawing of an oblique section through median axis (also adapted from Le Gros Clark13 showing how the laminae fuse together at the anterior pole The afferent ganglion cell axons that form the optic tract (OT) penetrate through the anterior surface to reach their target relay cells in the laminae (D) Drawing of the most dorsal lamina-layer 6--separated from the rest of the LGN The geometric shape is a hollow half-cone so that right and left LGNs placed back-to-back form in effect a single cone Note also the position ofthe RTN shown here as a striped bar relative to lamina 6 The position of the striped bar shows that the RTN makes direct contact with lamina 6 at the edge ofthe lateral wing and also along the ventral edges (E - F) Schematic drawings adapted from Connolly and Van Essen24 that show how a 3-dimensional lamina-lamina 6--can be transformed into a 2-dimensional triangular figure lamina 6 is removed and its wings unfolded (E) creating a slightly asymmetric triangular figure (F) which is adjusted to an oblong shape (G) in order to superimshypose a grid matrix with minimal distortion The grid plots locations of TC cells that represent various isoelevations and isoazimuths in the VF locations derived from the experimental observations published by Malpeli and Baker 25 Note the relatively large amounts of laminar surface allocated to central vision (0 0

- 30 0) as compared

to peripheral vision (30 0 - 80 0)

characteristics (1) Spindle bursts must move simultaneously through both geniculate nuclei This pattern of movement is consistent with anatomical studies in primates that found axonal projections linking the right and left RTNs27-28 and with experimental studies in cats that found spindles appearing simultaneously in both right and left thalami 29 (2) Spindle waves must enter the ventral edges of the LGN first and move ventrodorsally in a highly coherent pattern-moving in effect as a standing wave This pattern of movement is consistent with in vitro experiments using sagittal slices from a ferret LGN where spindle waves originated spontaneously at the edge of a slice in an area which contains cells that represent peripheral vision then propagated toward that area of the slice containing cells that represent central vision in the ferret 3o

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 129

VF

PG BIlateral receptive lleJd of PVN YI(j Inward dmKooflality Adapled

0-- from Mortgr at at (1987)

V1

ibull t bull

RTN t t t t t t 1middot3 SECOlO BURSTS OF 7middot14 HZ SPiKES RECURRNG EVERY 3 10 SECONDS

To our knowledge the LGN is the only anatomical structure in the visual system that has the capacity of passively forcing a wave of excitation to flow across a conical surface thereby generating the sensation of a phosphene annulus that retains its symmetry as it shrinks in diameter The retina has a circular anatomy but it is not likely that the mechanical deformation of the retina would produce a wave that began simultaneously in all 3600 of the retinal rim nor that the symmetry of annular wave would be preserved as it flows inward toward the foveal region

The hypothesis presented here-that there is a structure in the visual system that imprints a conical shape on standing waves that move through it-explains

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 130

Figure 4 facing page Schematic drawing of contemporaneous events in selected regions of the visual processing hierarchy (A) The left and right RTNs fire spindle bursts simultaneously (B) The bursts pass through the right and left geniculate laminae as standing waves of depolarization entering from the ventral edges and moving ventrodorsally in parallel In order for the phosphene annulus to appear to be flowing at a constant rate the spindle wave flowing through the LCN must expand in width as it ascends ventrodorsally so that by the time the fill-in disk appears-when the center 30deg of the VF is covered by the phosphene annulus-the spindle wave must have expanded enough to activate relay cells in the most dorsal 50 of lamina 6 (C) Signals representing two complementary hemi-annuli are kept separate in the primary visual cortices (area VI) (D) Signals representing the two hemi-annuli are integrated into signals of a single annulus when they reach area PC in the posterior parietal cortex where the receptive fields of single parietal visual neurons have the capacity to register bilateral signals that exhibit opponent vector movement (that is signals converging from opposite directions along the central axes-as if an object were moving away from the viewer)46 Neurons in area PC also integrate wavelength (color) signals from the extrastriate visual pathway with signals about brightness motion and depth from the parietal visual pathway to compose a representation of an object in space-in this case of an annulus that appears to recede 32

the authors experience during MRI when he observed a continuous succession of receding annuli every 2 seconds in this view the energy of the electroshymagnetic bombardment when released during precessional relaxation flows through the geniculate laminae in the same way that the RTN spindle bursts do that is as a standing wave and thus the visual epiphenomenon is the same in both cases if the subject keeps the eyes focused straight ahead and the attention fixated In a study of phosphenes evoked by electricity in conjunction with hallucinogenic drugs Knoll Kugler Hofer and Lawder found that each subject sees specific kinds of phosphene at different frequencies and that these frequency-specific images are stable enough to be reproduced after six months31

They conclude that the tunability of the electrical stimulation frequenshycies within the EEG range to various definable phosphenes requires the existence of a resonance system One mechanism contributing to that resonance system may be the functional anatomy of the LGN

The colors of receding annuli as functions of geniculate laminar anatomy The colors of receding annuli phosphenes are consistent with the patterns of discharge spindle waves can be expected to stimulate as they move through

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 131

geniculate laminae As shown in Figure 5 the six laminae differ (1) in the types of wavelength signals relayed (2) in physical size and (3) in the area of the VF represented 24-25 Only 4 out of 6 laminae Cparvocellular layers 3shy6) contain TC cells that relay wavelength signals the other 2 laminae (magnocellular layers 1 and 2) do not encode wavelength Among parvocelshylular laminae only lamina 6 the longest and most dorsal layer contains TC cells that can represent the far periphery of the VF (from 800 to 50deg of isoeccenshytdeity) therefore when the spindle wave enters the peripheral VF only those wavelengths relayed by lamina 6 will participate in composing a cortical lightness record (See Zeki)32

I n lamina 6 ganglion cell axons arriving from the retina carry two kinds of wavelength signals (1) center-ON signals from medium-wavelength cones (M-cone center-ON) and long-wavelength cones (L-cone centershy

ON)33-35 Using the cone spectral sensitivity curves (adapted from Marks et al 36) we average the wavelengths that elicit maximal responses for M-cones (535 nanometers) and L-cones (520 nm) which yields a mean wavelength value of 550 nm In humans this wavelength generates a sensation of green or yellowshygreen the sensation observed by the author

As the spindle burst moves ventrodorsally it reaches the dorsal areas in the geniculate laminae which contain TC cells representing the central 0deg to 20deg of isoeccentrieity in the VE All 4 parvocellular laminae have TC cells which are potentially capable of representing this central region of vision but the authors observation that the color of the filling-in disk changed from green to blue implies that in the early years of phosphene induction the spindle wave must have remained close to the surface of the LGN stimulating only laminae 5 and 6 which generates a sensation of yellow-green When the fill-in disk was observed to change color from green to blue the spindle wave must have been rechanneled so that it began to penetrate below laminae 5 and 6 and to activate laminae 3 and 4 the only laminae that relay blue-sensitive signals (Sshycone center-ON signals)3 In light of the authors MRI experience it seems likely that a spindle wave requires a minimum of 2 seconds to reach the blueshysensitive cells of laminae 4 therefore during MRI when the receding annuli disappeared after 2 seconds half the normal duration the fill-disk had a green color even though it had long since change to blue in other induction settings with a 4-second trajectory

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 132

A REPRESENTATION OF THE VISUAL FIELD IN EACH LAMINA

orooqUtftc O-u OCIJ1SALfIOLI (I01flAj

0

10

20

30

40 n50 Of

60

70

20 loO 1Mgr_ II~ o UIpoundAS65 mn1MY-o actlvncL ~~~r

Jll-COMcetlImiddot~

II LAYERSU 3 GatQYancetl~ (1) ucon ceom-oyenF (2)l~cen()FF 3) ~ cenloH

II~ cng1loqctWIIIfNla

iICINe -- (t81Otdb1t1d~OH (2)~

80

B CONE SPECTRAL SENSITIVITY CURVES

S-COHS

WAVIlLllNG1llS OF UGHT IH NANOMllTERS (NM)

Figure 5 Phosphene color as a function of ganglion cell distribution in parvocellular laminae (Aj Schematic drawing ofthe proportion ofthe VF represented in each laminae The proportions shown here are based on the work of Connolly and Van Essen24 The

far periphery of vision (50 0 to 80 0 of isoeccentricity) is represented in only two laminae-laminae 1 and 6-and of these two only lamina 6 is a parvocelLular lamina capable ofencoding wavelength signals Therefore only those wavelengths relayed by lamina 6 will participate in forming a cortical lighmess record for the far periphery of the VP (B) Cone spectral sensitivity curves (adapted from Marks et al)36 Using these cone sensitivity curves we can estimate the sensation stimulated by a spindle wave moving through lamina 6 by averaging the wavelengths that elicit maximal responses for M-cones (535 nanomeshyters) and L-cones (520 nm) which yields a mean wavelength value of550 nm In humans this generates a sensation of green or yellow-green the sensation observed by the author when the receding annulus enters at the far periphery of the VP For a calculation of the cortical lightness record when a spindle wave moves through 20deg to 0deg ofthe VF stimulating all 4 parvocelfular laminae see the text and Figure 6

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 133

Once the spindle wave penetrates to laminae 3 and 4 it may activate all 4 parvocellular laminae stimulating TC cells to send contradictory wavelength signals for the same retinotopic location the signals sent from laminae 4 and 3 will encode blue light (S-cone center-ON plus M-cone center-OFF and Lshycone center-OFF) while the signals sent from laminae 5 and 6 encode yellowshygreen light (M-cone center-ON plus L-cone center-ON) This kind of contrashydiction does not occur in normal retina-based perception where light energy striking the retina is structured by the retinas center-surround and colorshyopponent organization to encode only one set of wavelength signals for each spatial locus 32 In Figure 6 we estimate the cortical lightness record that results when contradictory wavelength signals compete to be represented in consciousshyness Our calculations suggest that the outcome will be a mean wavelength which in humans elicits a dark blue or violet sensation

PART II AMORPHOUS PHOSPHENES amp THALAMIC DELTA ACTMTY

M echanisms controlling the transition from spindle bursts to delta activity In the consensus scenario for the generation of NREMS16-20 we noted that the RTN shifts to firing spindle bursts

when polarization of thalamic cell membranes drops to V m = - 60 mV At the same time cortical cells begin oscillating with a synchronous slow rhythm laquo 1 Hz) Both processes further decrease the Vm of TC cell membranes When Vm = - 75 mY TC cells begin to generate their own intrinsic calcium currents which also decreases V m At V m = - 90 mV RTN neurons stop firing spindle bursts At the same time the TC cells begin firing low-threshold calcium spikes in alternation with after-hyperpolarizations (LTS-AHP) Because sensory relay neurons in the LGN are not linked to one another by locally projecting axons the firing of one TC cell does not excite its neighbor However a lack of local connectivity does not mean that TC cells occupying the same laminae release their AHP-LTS calcium spikes in a random distribshyution rather spikes are released simultaneously by groups of cells in synchrony with the advent of the cortical slow wave In effect the distribution of LTSshyAHP spikes firing in the LGN is determined by the spatial propagation of the cortical slow wave Thus the delta wave (1 to 4 Hz) activity detected by cortical EEG during NREMS is a product of the interaction between the AHP-LTS calcium spikes released by TC cells and the cortical slow rhythm

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 134

CORTICAL PROCESSING OF CONTRADICTORY

WAVELENGTH SIGNALS

KEY _ Cells firing

cJ Cononol firing

Assume that as a spind6e wave moves through the LGNlt fires simultaneously aU the TC cells that represent a particular reUnoshytopic locus (x y) in each of the six laminae As a result cortical cells engaged In the higher level processing of visual signals will receive more wavelength signals representing retina locus (x y) than are generated by normal perception laquo and some of these afferent wavelength signals may contradict other signals arriving simultaneously

CORTICAL LIGHTNESS RECORD SlgnalSell

Intemal contradictions not congruent wilt pre

SmiddotON eristing neuron neta

s bullbull M-ON LmiddotON

3 bullbull M-OFF + L-OFF

a-ON 12

ROD-ON

No Internal eonlradlemiddot

--------1I =~8b~~~~~~~t signals

3+4

~ --OFF Excludes 6 Of 7 $J9n18

1+2 B-ON I

IWmiddotHmiddotI Signal Sell

1111111 No Intern1 conlrfldlcshy lion

Exelvdta 4 out of 7 efshy

bullbullbull bullbullbull ferant signals

No Intern1 contradic_ tionnee S-ON BshyOH and ROO-ON can all be coacllve at low lImlnance levels nef Ihe rod-eone break

ExchJde$ only 2 Ollt of 7 afferent signals

Figure 6 Selection of competing wavelength signals based on neuronal group selection This thought experiment is based on Edelman sconcept ofneuronal group selection 73 We assume that all possible combinations ofsignals will form sets and that all signal-sets will compete to make the most efficient match with pre-existing neuromd networks that have been forged over years ofnorma reti1U1-based perception We also assume that pre-existing neural networks are most likely to expedite those sets that satisfY 2 criteriI (J) the signals in a set do not contradict each other and (2) fower signals are excluded than in the other sets that satisfY the first criterion In our analysis Set 4 wins the competition because it does not contain internal contradictions and excludes fower signals (2 out of 7) than Set 3 excludes (4 out of7) It is not an internal contradiction that Set 4 contains both rods and cone Signtlls in normal retina-based perception when luminance levels approach the rod-cone break S-cone center-ON receptors send signas as do rod receptors and there is even evidence that rod activity may actually drive S-cone activity even after luminance levels foIl below the rod-cone break74 To calculate the cortical lightness record for Set 4 we average the wavelength that elicits maximal responses foom rods (511 nm) and for Sshycones (430 nm) which yields a mean wavelength of 470 nm which in humans results in a dark-blue or violet sensation

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 135

The cortical slow rhythm is an example of a generic pattern of neuronal excitashytion that occurs in large networks of neurons linked by local projections A recent experiment by Maeda Robinson and Kwana38 shows that networks of locally-connected neurons spontaneously generate periodic synchronized bursts of calcium transients that propagate across the network in an expanding spatial wave a pattern that represents a stable mode of firing towards which these neuronal networks relax following perturbations for example by electronic stimulation or by drugs Understanding the characteristics of these waves is an important prerequisite to understanding the mechanisms that produce the amorphous phosphene images as a visual epiphenomenon

To study the spontaneous periodic synchronized bursts the researchers prepared cultures of dissociated cortical neurons and allowed them to mature for several days in vitro (DIV) After 3 to 4 DIV when concenshy

trations of extracellular magnesium were low electrodes began to detect spontaneous synchronized bursts of low frequency calcium transients (between 01 and 1 Hz) that originated in different locations on the sheet every 10 to 20 seconds and spread across the sheet of cells at a relatively slow speed averaging 50 mmsecond The researchers could not predict where a wave would originate or where it would expand rather the initiation and expansion of waves was generated by spatial and temporal summation of a continuous random background of synaptic inputs including miniature spontaneous synaptic events but the pattern was not random since waves propagated sequentially from electrode to electrode as each local group of neurons charges up its neighboring nontefractory areas rather than in a random sequence of regions38

The excitability of the cells in the sheet determines the probability first that there will be a synchronous burst and second that it will spread in a particshyular direction Cells become more excitable as the cultures mature which means the refractory intervals between successive bursts were much shorter in mature cultures (gt 30 DIV) than in early cultures laquo 7 DIV) Some cells became so insensitive to inhibition that they continued to fire bursts even when extracellular concentrations of magnesium were relatively high Finally there were refractory periods of 5 to 10 seconds during which no bursts occurred even when an electrical stimulus was applied This refractory interval for cultured networks is slightly longer than the refractory interval observed of the cortical slow wave in vivo which 25 to 4 seconds 18- 19

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 136

Based on the observations about cortical slow waves we can predict that phosphenes generated as epiphenomena of delta wave activity will present the following signal characteristics (1) signals that appear at unpredictable locations in the VF (2) signals that expand and diverge asymmetrically following unpredictable trajectories which may encompass large areas of the VF (3) signals that move relatively slowly (50 mmsec) (4) signals that recur with a period of 2 to 4 seconds reflecting entrainment by the cortical slow wave (5) signals that do not terminate automatically after a predictable number of cycles

The spatial patterns of phosphene mists and thalamic delta waves are similar The spatiotemporal characteristics of amorphous phosphenes match the pattern of wave propagation associated with periodic spontashy

neous synchronized bursts in large neuron networks the amorphous phosphenes enter the visual field at unpredictable locations expand and diverge asymmetrically with a slow steady rate of flow follow trajectories that are unpredictable and exhibit a refractory interval The amorphous mists do appear to have a periodicity although the author is unable to sustain the vision while also counting the seconds therefore he is unable to determine if it compares to the period of the cortical slow wave (25 to 4 seconds) but his impression is that it feels roughly the same as as with receding annuli which recur at 5 seconds Also the refractory interval feels as if it decreases as the induction session is extended These similarities suggest that the amorphous phosphenes are generated by stage 2 NREMS delta wave activity which is an activity governed by the reverberation of the cortical slow wave in thalamoshycorticothalamic circuits The cortical slow wave is referred to the LGN where it modulates the firing of visual relay cells in the laminae and since relay cells do not have local dendritic connections the expansion of a wave of depolarshyizations moving from one relay cell to the next across in the laminar surface will mirror at least in part the expansion of the cortical wave that is spreading contemporaneously through locally-connected cortical cells

PART III RETENTION OF CONSCIOUSNESS

In a normal transition to NREMS the volley of synchronous spindle bursts that marks the onset of stage 2 NREMS overwhelms the normal firing pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 137

of thalamocortical cells preventing their relay of afferent sensory signals and inducing a loss of consciousness21 But the loss of consciousness cannot be timed precisely using cortical EEG the thalamus is too remote for the onset of spindling to be reliably detected by scalp electrodes39 In experiments with cats where electrodes could be implanted in the thalamus researchers found that spindling often reached peak levels of activity in the thalamus-a level of activity consonant with stage 2 NREMS-at a time when the cortical EEG was still showing intermittent desynchronizations a pattern characteristic of the drowsy stage 1 transition not a fully-established stage 2 NREMS episode4o

In other words there is a short period of time in which the synchronous rhythms of stage 2 NREMS are installed in the thalamus but not in the cortex where cortical neurons continue to depolarize in response to afferent sensory signals

T his finding suggests a possible explanation for the authors ability to retain consciousness while spindle bursts are sweeping through the LGN if he is able to extend the duration of this time lag between

the onset of spindling in the thalamus and spindling in the cortex if he is able to stimulate the visual cortices in such a way that they continue to depolarize then he may be able to keep on processing visual signals-to remain visually aware-even after the non-visual thalamus and non-visual cortex become entrained by synchronous sleep rhythms The authors induction technique includes several behaviors which are known to enhance the responsiveness of visual neurons-eye movements attentive fixation and an attitude of expectancy

Effects of eye movements and attention on the LGN Sustained convergence causes periorbital proprioceptors to send excitatory feedback directly to the LGN41 Also convergence further enhances the excitability of geniculate cells by stimulating the superior collicus (SC) which sends its own excitatory signals to the LGN42-43 These signals from the SC are known to selectively enhance the excitability of visual relay cells that represent the periphery of vision44 We know in the authors case that the SC is being stimulated because he is able to keep on fixating an ability which would normally be lost during the transishytion to NREMS45 The ability to fixate can be retained however if the SC is stimulated (even if stimulated during NREMS)46

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 138

Effects of eye movement attention and expectancy on the primary visual cortex The PET study of mental imagery by Kosslyn et al 3 showed that even a baseline resting state of relaxed immobile expectancy can generate signifishycant increases in neuronal activity in the primary visual cortices Further increases can be induced by sustained eye movements

A sustained convergence will release a stream of ponto-geniculo-occipital (PGO) waves These PGO waves called eye movement potentials or EMPs last only as long as the eye movement1747 whereas the PGO waves associated with rapid-eye-movement sleep (REMS) fire continually for the duration of the REMS episode Both REMS-related PGO waves and EMPs have the same desynchronizing effect on the visual pathways they move through the LGN depolarizing the thalamocortical cells which relay the signals to cortical neurons The responsivity of neurons in the primary visual cortices is enhanced by the stimulation of PGO waves 1747-49 If the passage of EMPs causes the genicushylate relay cells and their cortical targets to depolarize regularly then a volley of 4 spindle bursts moving through the same pathways will register as just another series of depolarizations in effect the spindle bursts are processed by the visual system as if they were sensory signals sent from the retina rather than an event stimulated by endogenous mechanisms

T he impact of eye movements and ftxation on the parietal visual cortex Convergence and attentive fixation will also enhance the responsiveness of light-sensitive parietal visual neurons (PVNs) in area PG of the

posterior parietal cortex 50 In experiments where monkeys are trained to fix their attention on a screen-and to keep on fixating even if no targets appearshythe excitability of these light-sensitive PVNs increases by as much as 350 51

52-53Responsiveness is also facilitated by the angle of gaze Also area PG is the first region in the visual pathways containing individual neurons with the capacity to respond to large bilateral stimuli moving in opposite directions along the central meridians of vision (opponent vector motion) 853-55 Facilitation of PVNs in area PG has the effect of sensitizing the subject to bilateral opponent vector motion and this is especially true if the movement appears in the periphery of the VE 8

Intracortical ampliftcation and feedback to the LGN When PGO waves and signals from the SC arrive in the primary visual cortex they may be relatively weak however weak signals can be amplified by reverberating in large networks

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 139

of cortical cells linked by local projection 56 There are nine times as many excitatory links among cortical cells as there are projections from the visual cortex to the LGN an imbalance which suggests leads Suarez Koch and Douglas to propose that geniculate input provides only a minor fraction of the excitatory input the majority originating in neighboring and recurrently connected cortical cells57 If the excitabiliry of cortical neurons is slightly higher than normal then this process of amplification may continue even after the LGN signals that initiated the reverberation are no longer being transmitted by the LGN ( a hysteretic mode of operation) 57

Feedback from hyperexcited cortical neurons will stream back to the LGN via corticogeniculate projections which outnumber geniculocortical projections ten-to-one One effect of this feedback is that the LGN is

able to absorb large amounts of information flowing back from the cortex 58

As signals reverberate back and forth in thalamocorticothalamic circuits a matching process takes place those geniculate relay cells that fire in patterns consistent with the firing patterns of active cortical cells will have their responshysivity enhanced while those geniculate cells that fire in patterns not consistent with cortical cells will be suppressed 59

Preservation of consciousness by selective facilitation of the visual pathways By combining all of the facilitatory effects produced by the authors eye movements and attentive fixation-(l) stimulation of the LGN by feedback from periorbital proprioception both directly and indirectly via the SC (2) the release of PGO waves (EMPs) that facilitate neurons in the LGN and primary visual cortex as they pass (3) the facilitation of the primary visual cortex by a state of relaxed immobile expectancy (4) attentive fixation and angle of gaze that facilitate PVNs in area PG (5) intracortical amplification of signals received from the LGN and (6) corticogeniculate feedback that stimulates the LGN-we delineate a circuit of enhanced excitability that extends from the LGN through the post-geniculate visual heirarchy to area PG where signals are integrated into representations of objects

The hyperexcitability of neurons all along the post-geniculate visual pathways creates conditions in the visual cortices which are similar to those present during EEG-desynchronized states of waking and REMS Therefore neurons in the visual pathways are too excitable to be entrained by synchronous bursting

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 140

patterns when spindle waves move through them instead the spindle bursts stimulate visual neurons to depolarize and then recover as happens in response to afferent sensory signals during waking states It is important to note that for this to occur none of the constituent neuron assemblies is required to perform an abnormal operation the abnormality is a function of the authors intent to activate contemporaneously neuron assemblies that would not normally be co-activated

PART IV HYPNOTIC ANALGESIA

Manipulation of spatial attention as a method for alleviating pain sensations In a theoretical article on the neurophysiology of hypnosis Crawford and Gruzelier60 propose that variations in hypnotizability are function of variability in the efficiency of the frontolimbic (anterior) attentional system in humans high-hypnotizables are better able to sustain focused attention on a task and to ignore extraneous stimuli than are low-hypnotizables

I na related empirical study that compares the use of attention by subjects with high versus low hypnotizability Crawford Brown and Moon61 report that highly hypnotizable persons continue to show physiological reactivity

while cognitively not perceiving the painful stimuli Through disattentional processes they can dissociate themselves from the awareness of pain The authors phosphene induction behaviors-and the cutaneous analgesia he experishyences-appear to involve the same kind of behaviors that is a mobilization of frontolimbic attention used to withdraw attention from external stimuli and to concentrate it on internally-generated phosphene images This suggests the hypothesis that the mechanisms that generate phosphenes might also produce hypnotic analgesia There are several ways that visual signals and pain signals might interact to produce this analgesia

Competition between pain and vision signals for limbic registration The fully-developed sensation of pain requires integration of rwo kinds of informashytion Signals that encode the location and intensity of a noxious stimulus (nociceptive signals) are relayed via the thalamus to the somatosensory cortices which registers only the sensory-discriminative aspects of pain perception62 before reaching consciousness the nociceptive signals must be sent to the limbic

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 141

system where they are linked with signals from long-term memory that encode the affective significance the stimulus has acquired for that individual Studies of brain metabolism show this linking of somatosensory information with limbic associations takes place in the anterior cingulate (CG) and anterior insula62-64

PET studies also show that the anterior CG is activated when subjects shift their spatial attention in response to expectations as to where

66stimuli will next appear65- This is precisely what takes place during the state of immobile expectancy that induces phosphenes Since visual signals and nociceptive signals both require limbic enhancement which is only possible if they get access to the anterior CG there might be conditions in which the two types of afferent sensory signals have to compete for that access In a theoretical article on the mechanisms of attention Posner and Rothbart67

propose that visual signals can interfere with nociceptive signals by blocking access to the anterior CG As behavioral evidence they cite studies showing that when young infants make distress calls they can be distracted by the presentation of a new visual stimulus We have shown the evidence of such control at about three months Orienting to visual events can be employed to quiet or calm negative vocalizations However the distress appears to be maintained and reappears when the infants attention to the stimulus is reduced Caregivers also report the use or visual orienting to block overt manifestations of distress at about this age 67

The effects of disattention on the somatosensory cortices If there is a competition between visual signals and nociceptive signals for access to the anterior CG it is likely that the competition will be affected by the relative volume of signals received A recent study suggests that focusing attention on internally-generated visual stimuli may reduce the number of nociceptive signals relayed by the somatosensory cortices Drevets Burton Videen Snyder Simpson and Raichle68 have shown that the mere anticipation of a touch at a specific cutaneous site increases the flow of blood to those cortical somatosenshysory neurons that are linked with that site where touch is expected and decreases the flow of blood to neurons linked with sites where touch is not expected In this experiment the researchers designated touch as the behaviorally significant sensory stimulus but their findings suggest that the outcome could be reversed if the instructions were reversed if subjects were

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page J42

instructed to direct attention away from a cutaneous site where a noxious stimulus was being applied if they were instructed to relax close their eyes and concentrate on the play of phosphenes in the visual field as the behaviorally significant sensory stimulus then it would be reasonable to expect that the flow of blood would decrease to the somatosensory neurons linked with the cutaneous stimulus and that the flow of blood would increase to the visual cortices The decrease in blood flow to somatosensory neurons implies less neuronal activity which implies that fewer signals are being sent forward to the anterior CG than would have been sent if instead the subject were treating the touch as the behaviorally significant sensory stimulus If fewer pain signals arrive at the anterior it is reasonable to infer that the conscious experience of pain will be muted by the diversion of attention to internal visual stimuli

Differential impact of sleep rhythms in the visual and nonvisual thalamus There is another mechanism that might also contribute to the analgesic effect of inducing sleep rhythms PET studies show that

the thalamus is involved in the relay of nociceptive signals to the cortex63 although some confusion remains about which kinds of signals are relayed by which subregions in the thalamus62 One thalamic site clearly identified by anatomical studies as a relay for nociceptive signals is the ventroposterior lateral nucleus (VPL)69 If synchronous sleep rhythms are active in the thalamus we can reasonably expect that the VPL will itself be entrained by synchronous oscillations and that it will relay the sleep rhythms to somatosensory cortices Relay neurons in the VPL are not stimulated by feedback from eye movements and fixation as are relay neurons in the LGN which suggests that sleep rhythms may impede the relay of nociceptive signals via the VPL but not the relay of visual signals via the LGN

Brain waves associated with anesthesia and NREMS The hypothesis presented here-that consciousness can be preserved despite the presence of NREMS activity-is consistent with a recent report that the kinds of fast brain waves which are normally associated with conscious states are also present during NREMS and anesthesia two states which were thought to involve minimal brain activityJo Another recent study found that there is a close resemblance between the slow brain waves that appear during NREMS and those that appear during certain types of anesthesia71

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 143

bull bull bull

CONCLUSION

In this paper we have presented evidence supporting the hypothesis that phosphene images can be generated as an epiphenomena of thalamic spindle bursts and delta wave activity normally associated with NREMS The prereqshyuisites for inducing these sleep rhythm phosphenes are relaxed immobile expectancy sustained convergence and attentive fixation of an undifferentiated visual field Our hypothesis provides a necessary and sufficient explanation for the authors induction of phosphenes and perhaps also for the generation of phosphenes reported to appear spontaneously during the drowsy transition to sleep (hypnagogic states) during sensory deprivation or during certain kinds of prayer or meditation all of which involve a similar state of relaxed immobile expectancyJ2

CORRESPONDENCE Philip T Nicholson bull 52 Norfolk Road bull Chestnut Hill MA 02167

REFERENCES amp NOTES

1 M 1 Posner Modulation by Instruction Nature 373 (1995) pp 198-199 2 J Reissenweber E David amp M pfotenhauer Investigations of Psychological Aspects of

the Perception of Magnetophosphenes and Electrophosphenes Biomedizinische Tecknik 373 (1992) pp 42-45

3 S M Kosslyn W L Thompson 1 J Kim amp N M Alpert Topographical Representations of Mental Images in Primary Visual Cortex Nature 378 (I995) pp 496-498

4 P E Roland amp B Gulyas Visual Memory Visual Imagery and Visual Recognition of Large Field Patterns by the Human Brain Functional Anatomy by Positron Emission Tomography Cerebral Cortex 51 (1995) pp 79-93

5 H Benson The Relaxation Response (Morrow New York NY 1975) 6 ] H Schultz amp W Luthe Autogenic Training a Physiological Approach to Psychotherapy

(Grune amp Stratton New York NY 1969) 7 E Jacobson Progressive Relaxation (University of Chicago Press Chicago IL 1938) 8 M A Steinmetz BC Motter C] DuffY amp V B Mountcastle Functional Properties

of Parietal Visual Neurons Radial Organization of Directionalities Within the Visual Field Journal ofNeuroscience 71 (1987) pp 177-191

9 R R Edelman Magnetic Resonance Imaging of the Nervous System Discussions in Neuroscience 71 Elsevier Science Amsterdam (I990) also J H Newhouse amp ] I Wiener Understanding MRI 1st Ed (Little Brown Boston MA 1991)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 144

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

T he spatial features of receding annuli are functions of geniculate anatomy A spindle burst moving through the LGN to the cortex will acquire certain distinctive spatiotemporal characteristics because of the

unique curvilinear and laminar anatomy of the LGN A drawing of a macaque LGN based on a clay model constructed by Le Gros Clark23 is shown in Figure 3 The primate LGN is composed of six sheets of cells or laminae that fold over a central hylus In macaques the hylus rises steeply as it extends rostrocausally forming a high arch at the posterior pole in humans the hylus is much more shallow but the functional anatomy is thought to be essentially

23 24the same in both cases - The geometry of the arch forces each lamina to bend so as to constitute in effect one-half of a conical surface and each lamina with its hemi-conical shape contains visual relay cells representing the contralatshyeral half of the visual field (VF) Operating as a pair the complementary hemishycones of the right and left LGN form the functional equivalent of a single conical surface which represents the entire VE This conical geometry of the paired LGNs means a burst of otherwise formless excitation will acquire a distinctive shape as it propagates through the laminae of the LGN Imagine a horizontal section moving along the surface of a cone from base to apex that moving section forms an annulus that shrinks in diameter as it approaches the apex but retains its annular symmetry throughout its trajectory

Figure 3 also includes drawings that show how Connolly and Van Essen24

converted the 3-dimensional structure of lamina 6 the largest and most dorsal layer into a 2-dimensional map Connolly and Van Essen used data obtained by Malpelli and Baker25 to superimpose a grid that specifies the areas in lamina 6 that contain TC cells representing various degrees of isoeccentricity in the VE We will use this map at a later point to show how the movement of a spindle wave through a pair of LGNs correlates with what appears in the VE

The location of the RTN relative to the LGN is also shown in Figure 3 The RTN spindle pacemaker is a thin sheath of GABAnergic inhibitory cells that extends along the surface of the whole posterior ventral thalamus not just the LGN This extension brings the RTN into close proximity with the portion of the LGN (lateral wing) that protrudes out from the main body of the thalamus Some of RTN wraps around and beneath the ventral edges of the LGN26 The RTN comes closest to the LGN in two areas along the ventral edges of the longest laminae (lamina 6 and 1) and along the edge of the lateral

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 127

DORSAL POLE DORSALPOIEA B

L1 L4 L3 L

DORSAL POlE DORSAL POIE (FOVEA)

G LATERAL WING

25

DORSAL POL (FOVEA)

10 _DIAL

20 WING

~

wing These areas contain TC cells that represent the far periphery of the VE If a spindle burst enters the LGN at locations where laminae are in closest proximity to the RTN-along the ventral edges-then the discharge of TC cells will begin in the most ventral portions of the laminae the regions that represent the far periphery of the VE This matches the phosphene sequence observed by the author

Our hypothesis about how this proximity between RTN and LGN affects the trajectory of spindle waves is illustrated in Figure 4 We propose that it is not possible for the author to observe a thin annulus of phosphene sweeping in from all 3600 of the peripheral VF unless spindle bursts exhibit the following

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 128

Figure 3 [facing page Drawings of primate geniculate anatomy and functional anatomy relevant to the generation ofphosphenes (A) Anterior view ofa macaque monkey LGN based on a clay model reconstruction by Le Gros Clark 23 (B) Posterior view ofthe same model showing 6 laminae folded over a central hylus to form lateral and medial wings with the hylus arching steeply upward near the posterior pole to shape the laminae into layers of hollow half-cones nested together Note that the lateral wing of the LGN is slightly larger than the medial wing so that in situ the lateral wing protrudes out from the main body of the thalamus creating a small knob visible during dissection 26 (C) Schematic drawing of an oblique section through median axis (also adapted from Le Gros Clark13 showing how the laminae fuse together at the anterior pole The afferent ganglion cell axons that form the optic tract (OT) penetrate through the anterior surface to reach their target relay cells in the laminae (D) Drawing of the most dorsal lamina-layer 6--separated from the rest of the LGN The geometric shape is a hollow half-cone so that right and left LGNs placed back-to-back form in effect a single cone Note also the position ofthe RTN shown here as a striped bar relative to lamina 6 The position of the striped bar shows that the RTN makes direct contact with lamina 6 at the edge ofthe lateral wing and also along the ventral edges (E - F) Schematic drawings adapted from Connolly and Van Essen24 that show how a 3-dimensional lamina-lamina 6--can be transformed into a 2-dimensional triangular figure lamina 6 is removed and its wings unfolded (E) creating a slightly asymmetric triangular figure (F) which is adjusted to an oblong shape (G) in order to superimshypose a grid matrix with minimal distortion The grid plots locations of TC cells that represent various isoelevations and isoazimuths in the VF locations derived from the experimental observations published by Malpeli and Baker 25 Note the relatively large amounts of laminar surface allocated to central vision (0 0

- 30 0) as compared

to peripheral vision (30 0 - 80 0)

characteristics (1) Spindle bursts must move simultaneously through both geniculate nuclei This pattern of movement is consistent with anatomical studies in primates that found axonal projections linking the right and left RTNs27-28 and with experimental studies in cats that found spindles appearing simultaneously in both right and left thalami 29 (2) Spindle waves must enter the ventral edges of the LGN first and move ventrodorsally in a highly coherent pattern-moving in effect as a standing wave This pattern of movement is consistent with in vitro experiments using sagittal slices from a ferret LGN where spindle waves originated spontaneously at the edge of a slice in an area which contains cells that represent peripheral vision then propagated toward that area of the slice containing cells that represent central vision in the ferret 3o

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 129

VF

PG BIlateral receptive lleJd of PVN YI(j Inward dmKooflality Adapled

0-- from Mortgr at at (1987)

V1

ibull t bull

RTN t t t t t t 1middot3 SECOlO BURSTS OF 7middot14 HZ SPiKES RECURRNG EVERY 3 10 SECONDS

To our knowledge the LGN is the only anatomical structure in the visual system that has the capacity of passively forcing a wave of excitation to flow across a conical surface thereby generating the sensation of a phosphene annulus that retains its symmetry as it shrinks in diameter The retina has a circular anatomy but it is not likely that the mechanical deformation of the retina would produce a wave that began simultaneously in all 3600 of the retinal rim nor that the symmetry of annular wave would be preserved as it flows inward toward the foveal region

The hypothesis presented here-that there is a structure in the visual system that imprints a conical shape on standing waves that move through it-explains

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 130

Figure 4 facing page Schematic drawing of contemporaneous events in selected regions of the visual processing hierarchy (A) The left and right RTNs fire spindle bursts simultaneously (B) The bursts pass through the right and left geniculate laminae as standing waves of depolarization entering from the ventral edges and moving ventrodorsally in parallel In order for the phosphene annulus to appear to be flowing at a constant rate the spindle wave flowing through the LCN must expand in width as it ascends ventrodorsally so that by the time the fill-in disk appears-when the center 30deg of the VF is covered by the phosphene annulus-the spindle wave must have expanded enough to activate relay cells in the most dorsal 50 of lamina 6 (C) Signals representing two complementary hemi-annuli are kept separate in the primary visual cortices (area VI) (D) Signals representing the two hemi-annuli are integrated into signals of a single annulus when they reach area PC in the posterior parietal cortex where the receptive fields of single parietal visual neurons have the capacity to register bilateral signals that exhibit opponent vector movement (that is signals converging from opposite directions along the central axes-as if an object were moving away from the viewer)46 Neurons in area PC also integrate wavelength (color) signals from the extrastriate visual pathway with signals about brightness motion and depth from the parietal visual pathway to compose a representation of an object in space-in this case of an annulus that appears to recede 32

the authors experience during MRI when he observed a continuous succession of receding annuli every 2 seconds in this view the energy of the electroshymagnetic bombardment when released during precessional relaxation flows through the geniculate laminae in the same way that the RTN spindle bursts do that is as a standing wave and thus the visual epiphenomenon is the same in both cases if the subject keeps the eyes focused straight ahead and the attention fixated In a study of phosphenes evoked by electricity in conjunction with hallucinogenic drugs Knoll Kugler Hofer and Lawder found that each subject sees specific kinds of phosphene at different frequencies and that these frequency-specific images are stable enough to be reproduced after six months31

They conclude that the tunability of the electrical stimulation frequenshycies within the EEG range to various definable phosphenes requires the existence of a resonance system One mechanism contributing to that resonance system may be the functional anatomy of the LGN

The colors of receding annuli as functions of geniculate laminar anatomy The colors of receding annuli phosphenes are consistent with the patterns of discharge spindle waves can be expected to stimulate as they move through

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 131

geniculate laminae As shown in Figure 5 the six laminae differ (1) in the types of wavelength signals relayed (2) in physical size and (3) in the area of the VF represented 24-25 Only 4 out of 6 laminae Cparvocellular layers 3shy6) contain TC cells that relay wavelength signals the other 2 laminae (magnocellular layers 1 and 2) do not encode wavelength Among parvocelshylular laminae only lamina 6 the longest and most dorsal layer contains TC cells that can represent the far periphery of the VF (from 800 to 50deg of isoeccenshytdeity) therefore when the spindle wave enters the peripheral VF only those wavelengths relayed by lamina 6 will participate in composing a cortical lightness record (See Zeki)32

I n lamina 6 ganglion cell axons arriving from the retina carry two kinds of wavelength signals (1) center-ON signals from medium-wavelength cones (M-cone center-ON) and long-wavelength cones (L-cone centershy

ON)33-35 Using the cone spectral sensitivity curves (adapted from Marks et al 36) we average the wavelengths that elicit maximal responses for M-cones (535 nanometers) and L-cones (520 nm) which yields a mean wavelength value of 550 nm In humans this wavelength generates a sensation of green or yellowshygreen the sensation observed by the author

As the spindle burst moves ventrodorsally it reaches the dorsal areas in the geniculate laminae which contain TC cells representing the central 0deg to 20deg of isoeccentrieity in the VE All 4 parvocellular laminae have TC cells which are potentially capable of representing this central region of vision but the authors observation that the color of the filling-in disk changed from green to blue implies that in the early years of phosphene induction the spindle wave must have remained close to the surface of the LGN stimulating only laminae 5 and 6 which generates a sensation of yellow-green When the fill-in disk was observed to change color from green to blue the spindle wave must have been rechanneled so that it began to penetrate below laminae 5 and 6 and to activate laminae 3 and 4 the only laminae that relay blue-sensitive signals (Sshycone center-ON signals)3 In light of the authors MRI experience it seems likely that a spindle wave requires a minimum of 2 seconds to reach the blueshysensitive cells of laminae 4 therefore during MRI when the receding annuli disappeared after 2 seconds half the normal duration the fill-disk had a green color even though it had long since change to blue in other induction settings with a 4-second trajectory

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 132

A REPRESENTATION OF THE VISUAL FIELD IN EACH LAMINA

orooqUtftc O-u OCIJ1SALfIOLI (I01flAj

0

10

20

30

40 n50 Of

60

70

20 loO 1Mgr_ II~ o UIpoundAS65 mn1MY-o actlvncL ~~~r

Jll-COMcetlImiddot~

II LAYERSU 3 GatQYancetl~ (1) ucon ceom-oyenF (2)l~cen()FF 3) ~ cenloH

II~ cng1loqctWIIIfNla

iICINe -- (t81Otdb1t1d~OH (2)~

80

B CONE SPECTRAL SENSITIVITY CURVES

S-COHS

WAVIlLllNG1llS OF UGHT IH NANOMllTERS (NM)

Figure 5 Phosphene color as a function of ganglion cell distribution in parvocellular laminae (Aj Schematic drawing ofthe proportion ofthe VF represented in each laminae The proportions shown here are based on the work of Connolly and Van Essen24 The

far periphery of vision (50 0 to 80 0 of isoeccentricity) is represented in only two laminae-laminae 1 and 6-and of these two only lamina 6 is a parvocelLular lamina capable ofencoding wavelength signals Therefore only those wavelengths relayed by lamina 6 will participate in forming a cortical lighmess record for the far periphery of the VP (B) Cone spectral sensitivity curves (adapted from Marks et al)36 Using these cone sensitivity curves we can estimate the sensation stimulated by a spindle wave moving through lamina 6 by averaging the wavelengths that elicit maximal responses for M-cones (535 nanomeshyters) and L-cones (520 nm) which yields a mean wavelength value of550 nm In humans this generates a sensation of green or yellow-green the sensation observed by the author when the receding annulus enters at the far periphery of the VP For a calculation of the cortical lightness record when a spindle wave moves through 20deg to 0deg ofthe VF stimulating all 4 parvocelfular laminae see the text and Figure 6

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 133

Once the spindle wave penetrates to laminae 3 and 4 it may activate all 4 parvocellular laminae stimulating TC cells to send contradictory wavelength signals for the same retinotopic location the signals sent from laminae 4 and 3 will encode blue light (S-cone center-ON plus M-cone center-OFF and Lshycone center-OFF) while the signals sent from laminae 5 and 6 encode yellowshygreen light (M-cone center-ON plus L-cone center-ON) This kind of contrashydiction does not occur in normal retina-based perception where light energy striking the retina is structured by the retinas center-surround and colorshyopponent organization to encode only one set of wavelength signals for each spatial locus 32 In Figure 6 we estimate the cortical lightness record that results when contradictory wavelength signals compete to be represented in consciousshyness Our calculations suggest that the outcome will be a mean wavelength which in humans elicits a dark blue or violet sensation

PART II AMORPHOUS PHOSPHENES amp THALAMIC DELTA ACTMTY

M echanisms controlling the transition from spindle bursts to delta activity In the consensus scenario for the generation of NREMS16-20 we noted that the RTN shifts to firing spindle bursts

when polarization of thalamic cell membranes drops to V m = - 60 mV At the same time cortical cells begin oscillating with a synchronous slow rhythm laquo 1 Hz) Both processes further decrease the Vm of TC cell membranes When Vm = - 75 mY TC cells begin to generate their own intrinsic calcium currents which also decreases V m At V m = - 90 mV RTN neurons stop firing spindle bursts At the same time the TC cells begin firing low-threshold calcium spikes in alternation with after-hyperpolarizations (LTS-AHP) Because sensory relay neurons in the LGN are not linked to one another by locally projecting axons the firing of one TC cell does not excite its neighbor However a lack of local connectivity does not mean that TC cells occupying the same laminae release their AHP-LTS calcium spikes in a random distribshyution rather spikes are released simultaneously by groups of cells in synchrony with the advent of the cortical slow wave In effect the distribution of LTSshyAHP spikes firing in the LGN is determined by the spatial propagation of the cortical slow wave Thus the delta wave (1 to 4 Hz) activity detected by cortical EEG during NREMS is a product of the interaction between the AHP-LTS calcium spikes released by TC cells and the cortical slow rhythm

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 134

CORTICAL PROCESSING OF CONTRADICTORY

WAVELENGTH SIGNALS

KEY _ Cells firing

cJ Cononol firing

Assume that as a spind6e wave moves through the LGNlt fires simultaneously aU the TC cells that represent a particular reUnoshytopic locus (x y) in each of the six laminae As a result cortical cells engaged In the higher level processing of visual signals will receive more wavelength signals representing retina locus (x y) than are generated by normal perception laquo and some of these afferent wavelength signals may contradict other signals arriving simultaneously

CORTICAL LIGHTNESS RECORD SlgnalSell

Intemal contradictions not congruent wilt pre

SmiddotON eristing neuron neta

s bullbull M-ON LmiddotON

3 bullbull M-OFF + L-OFF

a-ON 12

ROD-ON

No Internal eonlradlemiddot

--------1I =~8b~~~~~~~t signals

3+4

~ --OFF Excludes 6 Of 7 $J9n18

1+2 B-ON I

IWmiddotHmiddotI Signal Sell

1111111 No Intern1 conlrfldlcshy lion

Exelvdta 4 out of 7 efshy

bullbullbull bullbullbull ferant signals

No Intern1 contradic_ tionnee S-ON BshyOH and ROO-ON can all be coacllve at low lImlnance levels nef Ihe rod-eone break

ExchJde$ only 2 Ollt of 7 afferent signals

Figure 6 Selection of competing wavelength signals based on neuronal group selection This thought experiment is based on Edelman sconcept ofneuronal group selection 73 We assume that all possible combinations ofsignals will form sets and that all signal-sets will compete to make the most efficient match with pre-existing neuromd networks that have been forged over years ofnorma reti1U1-based perception We also assume that pre-existing neural networks are most likely to expedite those sets that satisfY 2 criteriI (J) the signals in a set do not contradict each other and (2) fower signals are excluded than in the other sets that satisfY the first criterion In our analysis Set 4 wins the competition because it does not contain internal contradictions and excludes fower signals (2 out of 7) than Set 3 excludes (4 out of7) It is not an internal contradiction that Set 4 contains both rods and cone Signtlls in normal retina-based perception when luminance levels approach the rod-cone break S-cone center-ON receptors send signas as do rod receptors and there is even evidence that rod activity may actually drive S-cone activity even after luminance levels foIl below the rod-cone break74 To calculate the cortical lightness record for Set 4 we average the wavelength that elicits maximal responses foom rods (511 nm) and for Sshycones (430 nm) which yields a mean wavelength of 470 nm which in humans results in a dark-blue or violet sensation

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 135

The cortical slow rhythm is an example of a generic pattern of neuronal excitashytion that occurs in large networks of neurons linked by local projections A recent experiment by Maeda Robinson and Kwana38 shows that networks of locally-connected neurons spontaneously generate periodic synchronized bursts of calcium transients that propagate across the network in an expanding spatial wave a pattern that represents a stable mode of firing towards which these neuronal networks relax following perturbations for example by electronic stimulation or by drugs Understanding the characteristics of these waves is an important prerequisite to understanding the mechanisms that produce the amorphous phosphene images as a visual epiphenomenon

To study the spontaneous periodic synchronized bursts the researchers prepared cultures of dissociated cortical neurons and allowed them to mature for several days in vitro (DIV) After 3 to 4 DIV when concenshy

trations of extracellular magnesium were low electrodes began to detect spontaneous synchronized bursts of low frequency calcium transients (between 01 and 1 Hz) that originated in different locations on the sheet every 10 to 20 seconds and spread across the sheet of cells at a relatively slow speed averaging 50 mmsecond The researchers could not predict where a wave would originate or where it would expand rather the initiation and expansion of waves was generated by spatial and temporal summation of a continuous random background of synaptic inputs including miniature spontaneous synaptic events but the pattern was not random since waves propagated sequentially from electrode to electrode as each local group of neurons charges up its neighboring nontefractory areas rather than in a random sequence of regions38

The excitability of the cells in the sheet determines the probability first that there will be a synchronous burst and second that it will spread in a particshyular direction Cells become more excitable as the cultures mature which means the refractory intervals between successive bursts were much shorter in mature cultures (gt 30 DIV) than in early cultures laquo 7 DIV) Some cells became so insensitive to inhibition that they continued to fire bursts even when extracellular concentrations of magnesium were relatively high Finally there were refractory periods of 5 to 10 seconds during which no bursts occurred even when an electrical stimulus was applied This refractory interval for cultured networks is slightly longer than the refractory interval observed of the cortical slow wave in vivo which 25 to 4 seconds 18- 19

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 136

Based on the observations about cortical slow waves we can predict that phosphenes generated as epiphenomena of delta wave activity will present the following signal characteristics (1) signals that appear at unpredictable locations in the VF (2) signals that expand and diverge asymmetrically following unpredictable trajectories which may encompass large areas of the VF (3) signals that move relatively slowly (50 mmsec) (4) signals that recur with a period of 2 to 4 seconds reflecting entrainment by the cortical slow wave (5) signals that do not terminate automatically after a predictable number of cycles

The spatial patterns of phosphene mists and thalamic delta waves are similar The spatiotemporal characteristics of amorphous phosphenes match the pattern of wave propagation associated with periodic spontashy

neous synchronized bursts in large neuron networks the amorphous phosphenes enter the visual field at unpredictable locations expand and diverge asymmetrically with a slow steady rate of flow follow trajectories that are unpredictable and exhibit a refractory interval The amorphous mists do appear to have a periodicity although the author is unable to sustain the vision while also counting the seconds therefore he is unable to determine if it compares to the period of the cortical slow wave (25 to 4 seconds) but his impression is that it feels roughly the same as as with receding annuli which recur at 5 seconds Also the refractory interval feels as if it decreases as the induction session is extended These similarities suggest that the amorphous phosphenes are generated by stage 2 NREMS delta wave activity which is an activity governed by the reverberation of the cortical slow wave in thalamoshycorticothalamic circuits The cortical slow wave is referred to the LGN where it modulates the firing of visual relay cells in the laminae and since relay cells do not have local dendritic connections the expansion of a wave of depolarshyizations moving from one relay cell to the next across in the laminar surface will mirror at least in part the expansion of the cortical wave that is spreading contemporaneously through locally-connected cortical cells

PART III RETENTION OF CONSCIOUSNESS

In a normal transition to NREMS the volley of synchronous spindle bursts that marks the onset of stage 2 NREMS overwhelms the normal firing pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 137

of thalamocortical cells preventing their relay of afferent sensory signals and inducing a loss of consciousness21 But the loss of consciousness cannot be timed precisely using cortical EEG the thalamus is too remote for the onset of spindling to be reliably detected by scalp electrodes39 In experiments with cats where electrodes could be implanted in the thalamus researchers found that spindling often reached peak levels of activity in the thalamus-a level of activity consonant with stage 2 NREMS-at a time when the cortical EEG was still showing intermittent desynchronizations a pattern characteristic of the drowsy stage 1 transition not a fully-established stage 2 NREMS episode4o

In other words there is a short period of time in which the synchronous rhythms of stage 2 NREMS are installed in the thalamus but not in the cortex where cortical neurons continue to depolarize in response to afferent sensory signals

T his finding suggests a possible explanation for the authors ability to retain consciousness while spindle bursts are sweeping through the LGN if he is able to extend the duration of this time lag between

the onset of spindling in the thalamus and spindling in the cortex if he is able to stimulate the visual cortices in such a way that they continue to depolarize then he may be able to keep on processing visual signals-to remain visually aware-even after the non-visual thalamus and non-visual cortex become entrained by synchronous sleep rhythms The authors induction technique includes several behaviors which are known to enhance the responsiveness of visual neurons-eye movements attentive fixation and an attitude of expectancy

Effects of eye movements and attention on the LGN Sustained convergence causes periorbital proprioceptors to send excitatory feedback directly to the LGN41 Also convergence further enhances the excitability of geniculate cells by stimulating the superior collicus (SC) which sends its own excitatory signals to the LGN42-43 These signals from the SC are known to selectively enhance the excitability of visual relay cells that represent the periphery of vision44 We know in the authors case that the SC is being stimulated because he is able to keep on fixating an ability which would normally be lost during the transishytion to NREMS45 The ability to fixate can be retained however if the SC is stimulated (even if stimulated during NREMS)46

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 138

Effects of eye movement attention and expectancy on the primary visual cortex The PET study of mental imagery by Kosslyn et al 3 showed that even a baseline resting state of relaxed immobile expectancy can generate signifishycant increases in neuronal activity in the primary visual cortices Further increases can be induced by sustained eye movements

A sustained convergence will release a stream of ponto-geniculo-occipital (PGO) waves These PGO waves called eye movement potentials or EMPs last only as long as the eye movement1747 whereas the PGO waves associated with rapid-eye-movement sleep (REMS) fire continually for the duration of the REMS episode Both REMS-related PGO waves and EMPs have the same desynchronizing effect on the visual pathways they move through the LGN depolarizing the thalamocortical cells which relay the signals to cortical neurons The responsivity of neurons in the primary visual cortices is enhanced by the stimulation of PGO waves 1747-49 If the passage of EMPs causes the genicushylate relay cells and their cortical targets to depolarize regularly then a volley of 4 spindle bursts moving through the same pathways will register as just another series of depolarizations in effect the spindle bursts are processed by the visual system as if they were sensory signals sent from the retina rather than an event stimulated by endogenous mechanisms

T he impact of eye movements and ftxation on the parietal visual cortex Convergence and attentive fixation will also enhance the responsiveness of light-sensitive parietal visual neurons (PVNs) in area PG of the

posterior parietal cortex 50 In experiments where monkeys are trained to fix their attention on a screen-and to keep on fixating even if no targets appearshythe excitability of these light-sensitive PVNs increases by as much as 350 51

52-53Responsiveness is also facilitated by the angle of gaze Also area PG is the first region in the visual pathways containing individual neurons with the capacity to respond to large bilateral stimuli moving in opposite directions along the central meridians of vision (opponent vector motion) 853-55 Facilitation of PVNs in area PG has the effect of sensitizing the subject to bilateral opponent vector motion and this is especially true if the movement appears in the periphery of the VE 8

Intracortical ampliftcation and feedback to the LGN When PGO waves and signals from the SC arrive in the primary visual cortex they may be relatively weak however weak signals can be amplified by reverberating in large networks

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 139

of cortical cells linked by local projection 56 There are nine times as many excitatory links among cortical cells as there are projections from the visual cortex to the LGN an imbalance which suggests leads Suarez Koch and Douglas to propose that geniculate input provides only a minor fraction of the excitatory input the majority originating in neighboring and recurrently connected cortical cells57 If the excitabiliry of cortical neurons is slightly higher than normal then this process of amplification may continue even after the LGN signals that initiated the reverberation are no longer being transmitted by the LGN ( a hysteretic mode of operation) 57

Feedback from hyperexcited cortical neurons will stream back to the LGN via corticogeniculate projections which outnumber geniculocortical projections ten-to-one One effect of this feedback is that the LGN is

able to absorb large amounts of information flowing back from the cortex 58

As signals reverberate back and forth in thalamocorticothalamic circuits a matching process takes place those geniculate relay cells that fire in patterns consistent with the firing patterns of active cortical cells will have their responshysivity enhanced while those geniculate cells that fire in patterns not consistent with cortical cells will be suppressed 59

Preservation of consciousness by selective facilitation of the visual pathways By combining all of the facilitatory effects produced by the authors eye movements and attentive fixation-(l) stimulation of the LGN by feedback from periorbital proprioception both directly and indirectly via the SC (2) the release of PGO waves (EMPs) that facilitate neurons in the LGN and primary visual cortex as they pass (3) the facilitation of the primary visual cortex by a state of relaxed immobile expectancy (4) attentive fixation and angle of gaze that facilitate PVNs in area PG (5) intracortical amplification of signals received from the LGN and (6) corticogeniculate feedback that stimulates the LGN-we delineate a circuit of enhanced excitability that extends from the LGN through the post-geniculate visual heirarchy to area PG where signals are integrated into representations of objects

The hyperexcitability of neurons all along the post-geniculate visual pathways creates conditions in the visual cortices which are similar to those present during EEG-desynchronized states of waking and REMS Therefore neurons in the visual pathways are too excitable to be entrained by synchronous bursting

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 140

patterns when spindle waves move through them instead the spindle bursts stimulate visual neurons to depolarize and then recover as happens in response to afferent sensory signals during waking states It is important to note that for this to occur none of the constituent neuron assemblies is required to perform an abnormal operation the abnormality is a function of the authors intent to activate contemporaneously neuron assemblies that would not normally be co-activated

PART IV HYPNOTIC ANALGESIA

Manipulation of spatial attention as a method for alleviating pain sensations In a theoretical article on the neurophysiology of hypnosis Crawford and Gruzelier60 propose that variations in hypnotizability are function of variability in the efficiency of the frontolimbic (anterior) attentional system in humans high-hypnotizables are better able to sustain focused attention on a task and to ignore extraneous stimuli than are low-hypnotizables

I na related empirical study that compares the use of attention by subjects with high versus low hypnotizability Crawford Brown and Moon61 report that highly hypnotizable persons continue to show physiological reactivity

while cognitively not perceiving the painful stimuli Through disattentional processes they can dissociate themselves from the awareness of pain The authors phosphene induction behaviors-and the cutaneous analgesia he experishyences-appear to involve the same kind of behaviors that is a mobilization of frontolimbic attention used to withdraw attention from external stimuli and to concentrate it on internally-generated phosphene images This suggests the hypothesis that the mechanisms that generate phosphenes might also produce hypnotic analgesia There are several ways that visual signals and pain signals might interact to produce this analgesia

Competition between pain and vision signals for limbic registration The fully-developed sensation of pain requires integration of rwo kinds of informashytion Signals that encode the location and intensity of a noxious stimulus (nociceptive signals) are relayed via the thalamus to the somatosensory cortices which registers only the sensory-discriminative aspects of pain perception62 before reaching consciousness the nociceptive signals must be sent to the limbic

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 141

system where they are linked with signals from long-term memory that encode the affective significance the stimulus has acquired for that individual Studies of brain metabolism show this linking of somatosensory information with limbic associations takes place in the anterior cingulate (CG) and anterior insula62-64

PET studies also show that the anterior CG is activated when subjects shift their spatial attention in response to expectations as to where

66stimuli will next appear65- This is precisely what takes place during the state of immobile expectancy that induces phosphenes Since visual signals and nociceptive signals both require limbic enhancement which is only possible if they get access to the anterior CG there might be conditions in which the two types of afferent sensory signals have to compete for that access In a theoretical article on the mechanisms of attention Posner and Rothbart67

propose that visual signals can interfere with nociceptive signals by blocking access to the anterior CG As behavioral evidence they cite studies showing that when young infants make distress calls they can be distracted by the presentation of a new visual stimulus We have shown the evidence of such control at about three months Orienting to visual events can be employed to quiet or calm negative vocalizations However the distress appears to be maintained and reappears when the infants attention to the stimulus is reduced Caregivers also report the use or visual orienting to block overt manifestations of distress at about this age 67

The effects of disattention on the somatosensory cortices If there is a competition between visual signals and nociceptive signals for access to the anterior CG it is likely that the competition will be affected by the relative volume of signals received A recent study suggests that focusing attention on internally-generated visual stimuli may reduce the number of nociceptive signals relayed by the somatosensory cortices Drevets Burton Videen Snyder Simpson and Raichle68 have shown that the mere anticipation of a touch at a specific cutaneous site increases the flow of blood to those cortical somatosenshysory neurons that are linked with that site where touch is expected and decreases the flow of blood to neurons linked with sites where touch is not expected In this experiment the researchers designated touch as the behaviorally significant sensory stimulus but their findings suggest that the outcome could be reversed if the instructions were reversed if subjects were

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page J42

instructed to direct attention away from a cutaneous site where a noxious stimulus was being applied if they were instructed to relax close their eyes and concentrate on the play of phosphenes in the visual field as the behaviorally significant sensory stimulus then it would be reasonable to expect that the flow of blood would decrease to the somatosensory neurons linked with the cutaneous stimulus and that the flow of blood would increase to the visual cortices The decrease in blood flow to somatosensory neurons implies less neuronal activity which implies that fewer signals are being sent forward to the anterior CG than would have been sent if instead the subject were treating the touch as the behaviorally significant sensory stimulus If fewer pain signals arrive at the anterior it is reasonable to infer that the conscious experience of pain will be muted by the diversion of attention to internal visual stimuli

Differential impact of sleep rhythms in the visual and nonvisual thalamus There is another mechanism that might also contribute to the analgesic effect of inducing sleep rhythms PET studies show that

the thalamus is involved in the relay of nociceptive signals to the cortex63 although some confusion remains about which kinds of signals are relayed by which subregions in the thalamus62 One thalamic site clearly identified by anatomical studies as a relay for nociceptive signals is the ventroposterior lateral nucleus (VPL)69 If synchronous sleep rhythms are active in the thalamus we can reasonably expect that the VPL will itself be entrained by synchronous oscillations and that it will relay the sleep rhythms to somatosensory cortices Relay neurons in the VPL are not stimulated by feedback from eye movements and fixation as are relay neurons in the LGN which suggests that sleep rhythms may impede the relay of nociceptive signals via the VPL but not the relay of visual signals via the LGN

Brain waves associated with anesthesia and NREMS The hypothesis presented here-that consciousness can be preserved despite the presence of NREMS activity-is consistent with a recent report that the kinds of fast brain waves which are normally associated with conscious states are also present during NREMS and anesthesia two states which were thought to involve minimal brain activityJo Another recent study found that there is a close resemblance between the slow brain waves that appear during NREMS and those that appear during certain types of anesthesia71

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 143

bull bull bull

CONCLUSION

In this paper we have presented evidence supporting the hypothesis that phosphene images can be generated as an epiphenomena of thalamic spindle bursts and delta wave activity normally associated with NREMS The prereqshyuisites for inducing these sleep rhythm phosphenes are relaxed immobile expectancy sustained convergence and attentive fixation of an undifferentiated visual field Our hypothesis provides a necessary and sufficient explanation for the authors induction of phosphenes and perhaps also for the generation of phosphenes reported to appear spontaneously during the drowsy transition to sleep (hypnagogic states) during sensory deprivation or during certain kinds of prayer or meditation all of which involve a similar state of relaxed immobile expectancyJ2

CORRESPONDENCE Philip T Nicholson bull 52 Norfolk Road bull Chestnut Hill MA 02167

REFERENCES amp NOTES

1 M 1 Posner Modulation by Instruction Nature 373 (1995) pp 198-199 2 J Reissenweber E David amp M pfotenhauer Investigations of Psychological Aspects of

the Perception of Magnetophosphenes and Electrophosphenes Biomedizinische Tecknik 373 (1992) pp 42-45

3 S M Kosslyn W L Thompson 1 J Kim amp N M Alpert Topographical Representations of Mental Images in Primary Visual Cortex Nature 378 (I995) pp 496-498

4 P E Roland amp B Gulyas Visual Memory Visual Imagery and Visual Recognition of Large Field Patterns by the Human Brain Functional Anatomy by Positron Emission Tomography Cerebral Cortex 51 (1995) pp 79-93

5 H Benson The Relaxation Response (Morrow New York NY 1975) 6 ] H Schultz amp W Luthe Autogenic Training a Physiological Approach to Psychotherapy

(Grune amp Stratton New York NY 1969) 7 E Jacobson Progressive Relaxation (University of Chicago Press Chicago IL 1938) 8 M A Steinmetz BC Motter C] DuffY amp V B Mountcastle Functional Properties

of Parietal Visual Neurons Radial Organization of Directionalities Within the Visual Field Journal ofNeuroscience 71 (1987) pp 177-191

9 R R Edelman Magnetic Resonance Imaging of the Nervous System Discussions in Neuroscience 71 Elsevier Science Amsterdam (I990) also J H Newhouse amp ] I Wiener Understanding MRI 1st Ed (Little Brown Boston MA 1991)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 144

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

DORSAL POLE DORSALPOIEA B

L1 L4 L3 L

DORSAL POlE DORSAL POIE (FOVEA)

G LATERAL WING

25

DORSAL POL (FOVEA)

10 _DIAL

20 WING

~

wing These areas contain TC cells that represent the far periphery of the VE If a spindle burst enters the LGN at locations where laminae are in closest proximity to the RTN-along the ventral edges-then the discharge of TC cells will begin in the most ventral portions of the laminae the regions that represent the far periphery of the VE This matches the phosphene sequence observed by the author

Our hypothesis about how this proximity between RTN and LGN affects the trajectory of spindle waves is illustrated in Figure 4 We propose that it is not possible for the author to observe a thin annulus of phosphene sweeping in from all 3600 of the peripheral VF unless spindle bursts exhibit the following

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 128

Figure 3 [facing page Drawings of primate geniculate anatomy and functional anatomy relevant to the generation ofphosphenes (A) Anterior view ofa macaque monkey LGN based on a clay model reconstruction by Le Gros Clark 23 (B) Posterior view ofthe same model showing 6 laminae folded over a central hylus to form lateral and medial wings with the hylus arching steeply upward near the posterior pole to shape the laminae into layers of hollow half-cones nested together Note that the lateral wing of the LGN is slightly larger than the medial wing so that in situ the lateral wing protrudes out from the main body of the thalamus creating a small knob visible during dissection 26 (C) Schematic drawing of an oblique section through median axis (also adapted from Le Gros Clark13 showing how the laminae fuse together at the anterior pole The afferent ganglion cell axons that form the optic tract (OT) penetrate through the anterior surface to reach their target relay cells in the laminae (D) Drawing of the most dorsal lamina-layer 6--separated from the rest of the LGN The geometric shape is a hollow half-cone so that right and left LGNs placed back-to-back form in effect a single cone Note also the position ofthe RTN shown here as a striped bar relative to lamina 6 The position of the striped bar shows that the RTN makes direct contact with lamina 6 at the edge ofthe lateral wing and also along the ventral edges (E - F) Schematic drawings adapted from Connolly and Van Essen24 that show how a 3-dimensional lamina-lamina 6--can be transformed into a 2-dimensional triangular figure lamina 6 is removed and its wings unfolded (E) creating a slightly asymmetric triangular figure (F) which is adjusted to an oblong shape (G) in order to superimshypose a grid matrix with minimal distortion The grid plots locations of TC cells that represent various isoelevations and isoazimuths in the VF locations derived from the experimental observations published by Malpeli and Baker 25 Note the relatively large amounts of laminar surface allocated to central vision (0 0

- 30 0) as compared

to peripheral vision (30 0 - 80 0)

characteristics (1) Spindle bursts must move simultaneously through both geniculate nuclei This pattern of movement is consistent with anatomical studies in primates that found axonal projections linking the right and left RTNs27-28 and with experimental studies in cats that found spindles appearing simultaneously in both right and left thalami 29 (2) Spindle waves must enter the ventral edges of the LGN first and move ventrodorsally in a highly coherent pattern-moving in effect as a standing wave This pattern of movement is consistent with in vitro experiments using sagittal slices from a ferret LGN where spindle waves originated spontaneously at the edge of a slice in an area which contains cells that represent peripheral vision then propagated toward that area of the slice containing cells that represent central vision in the ferret 3o

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 129

VF

PG BIlateral receptive lleJd of PVN YI(j Inward dmKooflality Adapled

0-- from Mortgr at at (1987)

V1

ibull t bull

RTN t t t t t t 1middot3 SECOlO BURSTS OF 7middot14 HZ SPiKES RECURRNG EVERY 3 10 SECONDS

To our knowledge the LGN is the only anatomical structure in the visual system that has the capacity of passively forcing a wave of excitation to flow across a conical surface thereby generating the sensation of a phosphene annulus that retains its symmetry as it shrinks in diameter The retina has a circular anatomy but it is not likely that the mechanical deformation of the retina would produce a wave that began simultaneously in all 3600 of the retinal rim nor that the symmetry of annular wave would be preserved as it flows inward toward the foveal region

The hypothesis presented here-that there is a structure in the visual system that imprints a conical shape on standing waves that move through it-explains

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 130

Figure 4 facing page Schematic drawing of contemporaneous events in selected regions of the visual processing hierarchy (A) The left and right RTNs fire spindle bursts simultaneously (B) The bursts pass through the right and left geniculate laminae as standing waves of depolarization entering from the ventral edges and moving ventrodorsally in parallel In order for the phosphene annulus to appear to be flowing at a constant rate the spindle wave flowing through the LCN must expand in width as it ascends ventrodorsally so that by the time the fill-in disk appears-when the center 30deg of the VF is covered by the phosphene annulus-the spindle wave must have expanded enough to activate relay cells in the most dorsal 50 of lamina 6 (C) Signals representing two complementary hemi-annuli are kept separate in the primary visual cortices (area VI) (D) Signals representing the two hemi-annuli are integrated into signals of a single annulus when they reach area PC in the posterior parietal cortex where the receptive fields of single parietal visual neurons have the capacity to register bilateral signals that exhibit opponent vector movement (that is signals converging from opposite directions along the central axes-as if an object were moving away from the viewer)46 Neurons in area PC also integrate wavelength (color) signals from the extrastriate visual pathway with signals about brightness motion and depth from the parietal visual pathway to compose a representation of an object in space-in this case of an annulus that appears to recede 32

the authors experience during MRI when he observed a continuous succession of receding annuli every 2 seconds in this view the energy of the electroshymagnetic bombardment when released during precessional relaxation flows through the geniculate laminae in the same way that the RTN spindle bursts do that is as a standing wave and thus the visual epiphenomenon is the same in both cases if the subject keeps the eyes focused straight ahead and the attention fixated In a study of phosphenes evoked by electricity in conjunction with hallucinogenic drugs Knoll Kugler Hofer and Lawder found that each subject sees specific kinds of phosphene at different frequencies and that these frequency-specific images are stable enough to be reproduced after six months31

They conclude that the tunability of the electrical stimulation frequenshycies within the EEG range to various definable phosphenes requires the existence of a resonance system One mechanism contributing to that resonance system may be the functional anatomy of the LGN

The colors of receding annuli as functions of geniculate laminar anatomy The colors of receding annuli phosphenes are consistent with the patterns of discharge spindle waves can be expected to stimulate as they move through

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 131

geniculate laminae As shown in Figure 5 the six laminae differ (1) in the types of wavelength signals relayed (2) in physical size and (3) in the area of the VF represented 24-25 Only 4 out of 6 laminae Cparvocellular layers 3shy6) contain TC cells that relay wavelength signals the other 2 laminae (magnocellular layers 1 and 2) do not encode wavelength Among parvocelshylular laminae only lamina 6 the longest and most dorsal layer contains TC cells that can represent the far periphery of the VF (from 800 to 50deg of isoeccenshytdeity) therefore when the spindle wave enters the peripheral VF only those wavelengths relayed by lamina 6 will participate in composing a cortical lightness record (See Zeki)32

I n lamina 6 ganglion cell axons arriving from the retina carry two kinds of wavelength signals (1) center-ON signals from medium-wavelength cones (M-cone center-ON) and long-wavelength cones (L-cone centershy

ON)33-35 Using the cone spectral sensitivity curves (adapted from Marks et al 36) we average the wavelengths that elicit maximal responses for M-cones (535 nanometers) and L-cones (520 nm) which yields a mean wavelength value of 550 nm In humans this wavelength generates a sensation of green or yellowshygreen the sensation observed by the author

As the spindle burst moves ventrodorsally it reaches the dorsal areas in the geniculate laminae which contain TC cells representing the central 0deg to 20deg of isoeccentrieity in the VE All 4 parvocellular laminae have TC cells which are potentially capable of representing this central region of vision but the authors observation that the color of the filling-in disk changed from green to blue implies that in the early years of phosphene induction the spindle wave must have remained close to the surface of the LGN stimulating only laminae 5 and 6 which generates a sensation of yellow-green When the fill-in disk was observed to change color from green to blue the spindle wave must have been rechanneled so that it began to penetrate below laminae 5 and 6 and to activate laminae 3 and 4 the only laminae that relay blue-sensitive signals (Sshycone center-ON signals)3 In light of the authors MRI experience it seems likely that a spindle wave requires a minimum of 2 seconds to reach the blueshysensitive cells of laminae 4 therefore during MRI when the receding annuli disappeared after 2 seconds half the normal duration the fill-disk had a green color even though it had long since change to blue in other induction settings with a 4-second trajectory

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 132

A REPRESENTATION OF THE VISUAL FIELD IN EACH LAMINA

orooqUtftc O-u OCIJ1SALfIOLI (I01flAj

0

10

20

30

40 n50 Of

60

70

20 loO 1Mgr_ II~ o UIpoundAS65 mn1MY-o actlvncL ~~~r

Jll-COMcetlImiddot~

II LAYERSU 3 GatQYancetl~ (1) ucon ceom-oyenF (2)l~cen()FF 3) ~ cenloH

II~ cng1loqctWIIIfNla

iICINe -- (t81Otdb1t1d~OH (2)~

80

B CONE SPECTRAL SENSITIVITY CURVES

S-COHS

WAVIlLllNG1llS OF UGHT IH NANOMllTERS (NM)

Figure 5 Phosphene color as a function of ganglion cell distribution in parvocellular laminae (Aj Schematic drawing ofthe proportion ofthe VF represented in each laminae The proportions shown here are based on the work of Connolly and Van Essen24 The

far periphery of vision (50 0 to 80 0 of isoeccentricity) is represented in only two laminae-laminae 1 and 6-and of these two only lamina 6 is a parvocelLular lamina capable ofencoding wavelength signals Therefore only those wavelengths relayed by lamina 6 will participate in forming a cortical lighmess record for the far periphery of the VP (B) Cone spectral sensitivity curves (adapted from Marks et al)36 Using these cone sensitivity curves we can estimate the sensation stimulated by a spindle wave moving through lamina 6 by averaging the wavelengths that elicit maximal responses for M-cones (535 nanomeshyters) and L-cones (520 nm) which yields a mean wavelength value of550 nm In humans this generates a sensation of green or yellow-green the sensation observed by the author when the receding annulus enters at the far periphery of the VP For a calculation of the cortical lightness record when a spindle wave moves through 20deg to 0deg ofthe VF stimulating all 4 parvocelfular laminae see the text and Figure 6

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 133

Once the spindle wave penetrates to laminae 3 and 4 it may activate all 4 parvocellular laminae stimulating TC cells to send contradictory wavelength signals for the same retinotopic location the signals sent from laminae 4 and 3 will encode blue light (S-cone center-ON plus M-cone center-OFF and Lshycone center-OFF) while the signals sent from laminae 5 and 6 encode yellowshygreen light (M-cone center-ON plus L-cone center-ON) This kind of contrashydiction does not occur in normal retina-based perception where light energy striking the retina is structured by the retinas center-surround and colorshyopponent organization to encode only one set of wavelength signals for each spatial locus 32 In Figure 6 we estimate the cortical lightness record that results when contradictory wavelength signals compete to be represented in consciousshyness Our calculations suggest that the outcome will be a mean wavelength which in humans elicits a dark blue or violet sensation

PART II AMORPHOUS PHOSPHENES amp THALAMIC DELTA ACTMTY

M echanisms controlling the transition from spindle bursts to delta activity In the consensus scenario for the generation of NREMS16-20 we noted that the RTN shifts to firing spindle bursts

when polarization of thalamic cell membranes drops to V m = - 60 mV At the same time cortical cells begin oscillating with a synchronous slow rhythm laquo 1 Hz) Both processes further decrease the Vm of TC cell membranes When Vm = - 75 mY TC cells begin to generate their own intrinsic calcium currents which also decreases V m At V m = - 90 mV RTN neurons stop firing spindle bursts At the same time the TC cells begin firing low-threshold calcium spikes in alternation with after-hyperpolarizations (LTS-AHP) Because sensory relay neurons in the LGN are not linked to one another by locally projecting axons the firing of one TC cell does not excite its neighbor However a lack of local connectivity does not mean that TC cells occupying the same laminae release their AHP-LTS calcium spikes in a random distribshyution rather spikes are released simultaneously by groups of cells in synchrony with the advent of the cortical slow wave In effect the distribution of LTSshyAHP spikes firing in the LGN is determined by the spatial propagation of the cortical slow wave Thus the delta wave (1 to 4 Hz) activity detected by cortical EEG during NREMS is a product of the interaction between the AHP-LTS calcium spikes released by TC cells and the cortical slow rhythm

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 134

CORTICAL PROCESSING OF CONTRADICTORY

WAVELENGTH SIGNALS

KEY _ Cells firing

cJ Cononol firing

Assume that as a spind6e wave moves through the LGNlt fires simultaneously aU the TC cells that represent a particular reUnoshytopic locus (x y) in each of the six laminae As a result cortical cells engaged In the higher level processing of visual signals will receive more wavelength signals representing retina locus (x y) than are generated by normal perception laquo and some of these afferent wavelength signals may contradict other signals arriving simultaneously

CORTICAL LIGHTNESS RECORD SlgnalSell

Intemal contradictions not congruent wilt pre

SmiddotON eristing neuron neta

s bullbull M-ON LmiddotON

3 bullbull M-OFF + L-OFF

a-ON 12

ROD-ON

No Internal eonlradlemiddot

--------1I =~8b~~~~~~~t signals

3+4

~ --OFF Excludes 6 Of 7 $J9n18

1+2 B-ON I

IWmiddotHmiddotI Signal Sell

1111111 No Intern1 conlrfldlcshy lion

Exelvdta 4 out of 7 efshy

bullbullbull bullbullbull ferant signals

No Intern1 contradic_ tionnee S-ON BshyOH and ROO-ON can all be coacllve at low lImlnance levels nef Ihe rod-eone break

ExchJde$ only 2 Ollt of 7 afferent signals

Figure 6 Selection of competing wavelength signals based on neuronal group selection This thought experiment is based on Edelman sconcept ofneuronal group selection 73 We assume that all possible combinations ofsignals will form sets and that all signal-sets will compete to make the most efficient match with pre-existing neuromd networks that have been forged over years ofnorma reti1U1-based perception We also assume that pre-existing neural networks are most likely to expedite those sets that satisfY 2 criteriI (J) the signals in a set do not contradict each other and (2) fower signals are excluded than in the other sets that satisfY the first criterion In our analysis Set 4 wins the competition because it does not contain internal contradictions and excludes fower signals (2 out of 7) than Set 3 excludes (4 out of7) It is not an internal contradiction that Set 4 contains both rods and cone Signtlls in normal retina-based perception when luminance levels approach the rod-cone break S-cone center-ON receptors send signas as do rod receptors and there is even evidence that rod activity may actually drive S-cone activity even after luminance levels foIl below the rod-cone break74 To calculate the cortical lightness record for Set 4 we average the wavelength that elicits maximal responses foom rods (511 nm) and for Sshycones (430 nm) which yields a mean wavelength of 470 nm which in humans results in a dark-blue or violet sensation

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 135

The cortical slow rhythm is an example of a generic pattern of neuronal excitashytion that occurs in large networks of neurons linked by local projections A recent experiment by Maeda Robinson and Kwana38 shows that networks of locally-connected neurons spontaneously generate periodic synchronized bursts of calcium transients that propagate across the network in an expanding spatial wave a pattern that represents a stable mode of firing towards which these neuronal networks relax following perturbations for example by electronic stimulation or by drugs Understanding the characteristics of these waves is an important prerequisite to understanding the mechanisms that produce the amorphous phosphene images as a visual epiphenomenon

To study the spontaneous periodic synchronized bursts the researchers prepared cultures of dissociated cortical neurons and allowed them to mature for several days in vitro (DIV) After 3 to 4 DIV when concenshy

trations of extracellular magnesium were low electrodes began to detect spontaneous synchronized bursts of low frequency calcium transients (between 01 and 1 Hz) that originated in different locations on the sheet every 10 to 20 seconds and spread across the sheet of cells at a relatively slow speed averaging 50 mmsecond The researchers could not predict where a wave would originate or where it would expand rather the initiation and expansion of waves was generated by spatial and temporal summation of a continuous random background of synaptic inputs including miniature spontaneous synaptic events but the pattern was not random since waves propagated sequentially from electrode to electrode as each local group of neurons charges up its neighboring nontefractory areas rather than in a random sequence of regions38

The excitability of the cells in the sheet determines the probability first that there will be a synchronous burst and second that it will spread in a particshyular direction Cells become more excitable as the cultures mature which means the refractory intervals between successive bursts were much shorter in mature cultures (gt 30 DIV) than in early cultures laquo 7 DIV) Some cells became so insensitive to inhibition that they continued to fire bursts even when extracellular concentrations of magnesium were relatively high Finally there were refractory periods of 5 to 10 seconds during which no bursts occurred even when an electrical stimulus was applied This refractory interval for cultured networks is slightly longer than the refractory interval observed of the cortical slow wave in vivo which 25 to 4 seconds 18- 19

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 136

Based on the observations about cortical slow waves we can predict that phosphenes generated as epiphenomena of delta wave activity will present the following signal characteristics (1) signals that appear at unpredictable locations in the VF (2) signals that expand and diverge asymmetrically following unpredictable trajectories which may encompass large areas of the VF (3) signals that move relatively slowly (50 mmsec) (4) signals that recur with a period of 2 to 4 seconds reflecting entrainment by the cortical slow wave (5) signals that do not terminate automatically after a predictable number of cycles

The spatial patterns of phosphene mists and thalamic delta waves are similar The spatiotemporal characteristics of amorphous phosphenes match the pattern of wave propagation associated with periodic spontashy

neous synchronized bursts in large neuron networks the amorphous phosphenes enter the visual field at unpredictable locations expand and diverge asymmetrically with a slow steady rate of flow follow trajectories that are unpredictable and exhibit a refractory interval The amorphous mists do appear to have a periodicity although the author is unable to sustain the vision while also counting the seconds therefore he is unable to determine if it compares to the period of the cortical slow wave (25 to 4 seconds) but his impression is that it feels roughly the same as as with receding annuli which recur at 5 seconds Also the refractory interval feels as if it decreases as the induction session is extended These similarities suggest that the amorphous phosphenes are generated by stage 2 NREMS delta wave activity which is an activity governed by the reverberation of the cortical slow wave in thalamoshycorticothalamic circuits The cortical slow wave is referred to the LGN where it modulates the firing of visual relay cells in the laminae and since relay cells do not have local dendritic connections the expansion of a wave of depolarshyizations moving from one relay cell to the next across in the laminar surface will mirror at least in part the expansion of the cortical wave that is spreading contemporaneously through locally-connected cortical cells

PART III RETENTION OF CONSCIOUSNESS

In a normal transition to NREMS the volley of synchronous spindle bursts that marks the onset of stage 2 NREMS overwhelms the normal firing pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 137

of thalamocortical cells preventing their relay of afferent sensory signals and inducing a loss of consciousness21 But the loss of consciousness cannot be timed precisely using cortical EEG the thalamus is too remote for the onset of spindling to be reliably detected by scalp electrodes39 In experiments with cats where electrodes could be implanted in the thalamus researchers found that spindling often reached peak levels of activity in the thalamus-a level of activity consonant with stage 2 NREMS-at a time when the cortical EEG was still showing intermittent desynchronizations a pattern characteristic of the drowsy stage 1 transition not a fully-established stage 2 NREMS episode4o

In other words there is a short period of time in which the synchronous rhythms of stage 2 NREMS are installed in the thalamus but not in the cortex where cortical neurons continue to depolarize in response to afferent sensory signals

T his finding suggests a possible explanation for the authors ability to retain consciousness while spindle bursts are sweeping through the LGN if he is able to extend the duration of this time lag between

the onset of spindling in the thalamus and spindling in the cortex if he is able to stimulate the visual cortices in such a way that they continue to depolarize then he may be able to keep on processing visual signals-to remain visually aware-even after the non-visual thalamus and non-visual cortex become entrained by synchronous sleep rhythms The authors induction technique includes several behaviors which are known to enhance the responsiveness of visual neurons-eye movements attentive fixation and an attitude of expectancy

Effects of eye movements and attention on the LGN Sustained convergence causes periorbital proprioceptors to send excitatory feedback directly to the LGN41 Also convergence further enhances the excitability of geniculate cells by stimulating the superior collicus (SC) which sends its own excitatory signals to the LGN42-43 These signals from the SC are known to selectively enhance the excitability of visual relay cells that represent the periphery of vision44 We know in the authors case that the SC is being stimulated because he is able to keep on fixating an ability which would normally be lost during the transishytion to NREMS45 The ability to fixate can be retained however if the SC is stimulated (even if stimulated during NREMS)46

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 138

Effects of eye movement attention and expectancy on the primary visual cortex The PET study of mental imagery by Kosslyn et al 3 showed that even a baseline resting state of relaxed immobile expectancy can generate signifishycant increases in neuronal activity in the primary visual cortices Further increases can be induced by sustained eye movements

A sustained convergence will release a stream of ponto-geniculo-occipital (PGO) waves These PGO waves called eye movement potentials or EMPs last only as long as the eye movement1747 whereas the PGO waves associated with rapid-eye-movement sleep (REMS) fire continually for the duration of the REMS episode Both REMS-related PGO waves and EMPs have the same desynchronizing effect on the visual pathways they move through the LGN depolarizing the thalamocortical cells which relay the signals to cortical neurons The responsivity of neurons in the primary visual cortices is enhanced by the stimulation of PGO waves 1747-49 If the passage of EMPs causes the genicushylate relay cells and their cortical targets to depolarize regularly then a volley of 4 spindle bursts moving through the same pathways will register as just another series of depolarizations in effect the spindle bursts are processed by the visual system as if they were sensory signals sent from the retina rather than an event stimulated by endogenous mechanisms

T he impact of eye movements and ftxation on the parietal visual cortex Convergence and attentive fixation will also enhance the responsiveness of light-sensitive parietal visual neurons (PVNs) in area PG of the

posterior parietal cortex 50 In experiments where monkeys are trained to fix their attention on a screen-and to keep on fixating even if no targets appearshythe excitability of these light-sensitive PVNs increases by as much as 350 51

52-53Responsiveness is also facilitated by the angle of gaze Also area PG is the first region in the visual pathways containing individual neurons with the capacity to respond to large bilateral stimuli moving in opposite directions along the central meridians of vision (opponent vector motion) 853-55 Facilitation of PVNs in area PG has the effect of sensitizing the subject to bilateral opponent vector motion and this is especially true if the movement appears in the periphery of the VE 8

Intracortical ampliftcation and feedback to the LGN When PGO waves and signals from the SC arrive in the primary visual cortex they may be relatively weak however weak signals can be amplified by reverberating in large networks

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 139

of cortical cells linked by local projection 56 There are nine times as many excitatory links among cortical cells as there are projections from the visual cortex to the LGN an imbalance which suggests leads Suarez Koch and Douglas to propose that geniculate input provides only a minor fraction of the excitatory input the majority originating in neighboring and recurrently connected cortical cells57 If the excitabiliry of cortical neurons is slightly higher than normal then this process of amplification may continue even after the LGN signals that initiated the reverberation are no longer being transmitted by the LGN ( a hysteretic mode of operation) 57

Feedback from hyperexcited cortical neurons will stream back to the LGN via corticogeniculate projections which outnumber geniculocortical projections ten-to-one One effect of this feedback is that the LGN is

able to absorb large amounts of information flowing back from the cortex 58

As signals reverberate back and forth in thalamocorticothalamic circuits a matching process takes place those geniculate relay cells that fire in patterns consistent with the firing patterns of active cortical cells will have their responshysivity enhanced while those geniculate cells that fire in patterns not consistent with cortical cells will be suppressed 59

Preservation of consciousness by selective facilitation of the visual pathways By combining all of the facilitatory effects produced by the authors eye movements and attentive fixation-(l) stimulation of the LGN by feedback from periorbital proprioception both directly and indirectly via the SC (2) the release of PGO waves (EMPs) that facilitate neurons in the LGN and primary visual cortex as they pass (3) the facilitation of the primary visual cortex by a state of relaxed immobile expectancy (4) attentive fixation and angle of gaze that facilitate PVNs in area PG (5) intracortical amplification of signals received from the LGN and (6) corticogeniculate feedback that stimulates the LGN-we delineate a circuit of enhanced excitability that extends from the LGN through the post-geniculate visual heirarchy to area PG where signals are integrated into representations of objects

The hyperexcitability of neurons all along the post-geniculate visual pathways creates conditions in the visual cortices which are similar to those present during EEG-desynchronized states of waking and REMS Therefore neurons in the visual pathways are too excitable to be entrained by synchronous bursting

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 140

patterns when spindle waves move through them instead the spindle bursts stimulate visual neurons to depolarize and then recover as happens in response to afferent sensory signals during waking states It is important to note that for this to occur none of the constituent neuron assemblies is required to perform an abnormal operation the abnormality is a function of the authors intent to activate contemporaneously neuron assemblies that would not normally be co-activated

PART IV HYPNOTIC ANALGESIA

Manipulation of spatial attention as a method for alleviating pain sensations In a theoretical article on the neurophysiology of hypnosis Crawford and Gruzelier60 propose that variations in hypnotizability are function of variability in the efficiency of the frontolimbic (anterior) attentional system in humans high-hypnotizables are better able to sustain focused attention on a task and to ignore extraneous stimuli than are low-hypnotizables

I na related empirical study that compares the use of attention by subjects with high versus low hypnotizability Crawford Brown and Moon61 report that highly hypnotizable persons continue to show physiological reactivity

while cognitively not perceiving the painful stimuli Through disattentional processes they can dissociate themselves from the awareness of pain The authors phosphene induction behaviors-and the cutaneous analgesia he experishyences-appear to involve the same kind of behaviors that is a mobilization of frontolimbic attention used to withdraw attention from external stimuli and to concentrate it on internally-generated phosphene images This suggests the hypothesis that the mechanisms that generate phosphenes might also produce hypnotic analgesia There are several ways that visual signals and pain signals might interact to produce this analgesia

Competition between pain and vision signals for limbic registration The fully-developed sensation of pain requires integration of rwo kinds of informashytion Signals that encode the location and intensity of a noxious stimulus (nociceptive signals) are relayed via the thalamus to the somatosensory cortices which registers only the sensory-discriminative aspects of pain perception62 before reaching consciousness the nociceptive signals must be sent to the limbic

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 141

system where they are linked with signals from long-term memory that encode the affective significance the stimulus has acquired for that individual Studies of brain metabolism show this linking of somatosensory information with limbic associations takes place in the anterior cingulate (CG) and anterior insula62-64

PET studies also show that the anterior CG is activated when subjects shift their spatial attention in response to expectations as to where

66stimuli will next appear65- This is precisely what takes place during the state of immobile expectancy that induces phosphenes Since visual signals and nociceptive signals both require limbic enhancement which is only possible if they get access to the anterior CG there might be conditions in which the two types of afferent sensory signals have to compete for that access In a theoretical article on the mechanisms of attention Posner and Rothbart67

propose that visual signals can interfere with nociceptive signals by blocking access to the anterior CG As behavioral evidence they cite studies showing that when young infants make distress calls they can be distracted by the presentation of a new visual stimulus We have shown the evidence of such control at about three months Orienting to visual events can be employed to quiet or calm negative vocalizations However the distress appears to be maintained and reappears when the infants attention to the stimulus is reduced Caregivers also report the use or visual orienting to block overt manifestations of distress at about this age 67

The effects of disattention on the somatosensory cortices If there is a competition between visual signals and nociceptive signals for access to the anterior CG it is likely that the competition will be affected by the relative volume of signals received A recent study suggests that focusing attention on internally-generated visual stimuli may reduce the number of nociceptive signals relayed by the somatosensory cortices Drevets Burton Videen Snyder Simpson and Raichle68 have shown that the mere anticipation of a touch at a specific cutaneous site increases the flow of blood to those cortical somatosenshysory neurons that are linked with that site where touch is expected and decreases the flow of blood to neurons linked with sites where touch is not expected In this experiment the researchers designated touch as the behaviorally significant sensory stimulus but their findings suggest that the outcome could be reversed if the instructions were reversed if subjects were

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page J42

instructed to direct attention away from a cutaneous site where a noxious stimulus was being applied if they were instructed to relax close their eyes and concentrate on the play of phosphenes in the visual field as the behaviorally significant sensory stimulus then it would be reasonable to expect that the flow of blood would decrease to the somatosensory neurons linked with the cutaneous stimulus and that the flow of blood would increase to the visual cortices The decrease in blood flow to somatosensory neurons implies less neuronal activity which implies that fewer signals are being sent forward to the anterior CG than would have been sent if instead the subject were treating the touch as the behaviorally significant sensory stimulus If fewer pain signals arrive at the anterior it is reasonable to infer that the conscious experience of pain will be muted by the diversion of attention to internal visual stimuli

Differential impact of sleep rhythms in the visual and nonvisual thalamus There is another mechanism that might also contribute to the analgesic effect of inducing sleep rhythms PET studies show that

the thalamus is involved in the relay of nociceptive signals to the cortex63 although some confusion remains about which kinds of signals are relayed by which subregions in the thalamus62 One thalamic site clearly identified by anatomical studies as a relay for nociceptive signals is the ventroposterior lateral nucleus (VPL)69 If synchronous sleep rhythms are active in the thalamus we can reasonably expect that the VPL will itself be entrained by synchronous oscillations and that it will relay the sleep rhythms to somatosensory cortices Relay neurons in the VPL are not stimulated by feedback from eye movements and fixation as are relay neurons in the LGN which suggests that sleep rhythms may impede the relay of nociceptive signals via the VPL but not the relay of visual signals via the LGN

Brain waves associated with anesthesia and NREMS The hypothesis presented here-that consciousness can be preserved despite the presence of NREMS activity-is consistent with a recent report that the kinds of fast brain waves which are normally associated with conscious states are also present during NREMS and anesthesia two states which were thought to involve minimal brain activityJo Another recent study found that there is a close resemblance between the slow brain waves that appear during NREMS and those that appear during certain types of anesthesia71

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 143

bull bull bull

CONCLUSION

In this paper we have presented evidence supporting the hypothesis that phosphene images can be generated as an epiphenomena of thalamic spindle bursts and delta wave activity normally associated with NREMS The prereqshyuisites for inducing these sleep rhythm phosphenes are relaxed immobile expectancy sustained convergence and attentive fixation of an undifferentiated visual field Our hypothesis provides a necessary and sufficient explanation for the authors induction of phosphenes and perhaps also for the generation of phosphenes reported to appear spontaneously during the drowsy transition to sleep (hypnagogic states) during sensory deprivation or during certain kinds of prayer or meditation all of which involve a similar state of relaxed immobile expectancyJ2

CORRESPONDENCE Philip T Nicholson bull 52 Norfolk Road bull Chestnut Hill MA 02167

REFERENCES amp NOTES

1 M 1 Posner Modulation by Instruction Nature 373 (1995) pp 198-199 2 J Reissenweber E David amp M pfotenhauer Investigations of Psychological Aspects of

the Perception of Magnetophosphenes and Electrophosphenes Biomedizinische Tecknik 373 (1992) pp 42-45

3 S M Kosslyn W L Thompson 1 J Kim amp N M Alpert Topographical Representations of Mental Images in Primary Visual Cortex Nature 378 (I995) pp 496-498

4 P E Roland amp B Gulyas Visual Memory Visual Imagery and Visual Recognition of Large Field Patterns by the Human Brain Functional Anatomy by Positron Emission Tomography Cerebral Cortex 51 (1995) pp 79-93

5 H Benson The Relaxation Response (Morrow New York NY 1975) 6 ] H Schultz amp W Luthe Autogenic Training a Physiological Approach to Psychotherapy

(Grune amp Stratton New York NY 1969) 7 E Jacobson Progressive Relaxation (University of Chicago Press Chicago IL 1938) 8 M A Steinmetz BC Motter C] DuffY amp V B Mountcastle Functional Properties

of Parietal Visual Neurons Radial Organization of Directionalities Within the Visual Field Journal ofNeuroscience 71 (1987) pp 177-191

9 R R Edelman Magnetic Resonance Imaging of the Nervous System Discussions in Neuroscience 71 Elsevier Science Amsterdam (I990) also J H Newhouse amp ] I Wiener Understanding MRI 1st Ed (Little Brown Boston MA 1991)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 144

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

Figure 3 [facing page Drawings of primate geniculate anatomy and functional anatomy relevant to the generation ofphosphenes (A) Anterior view ofa macaque monkey LGN based on a clay model reconstruction by Le Gros Clark 23 (B) Posterior view ofthe same model showing 6 laminae folded over a central hylus to form lateral and medial wings with the hylus arching steeply upward near the posterior pole to shape the laminae into layers of hollow half-cones nested together Note that the lateral wing of the LGN is slightly larger than the medial wing so that in situ the lateral wing protrudes out from the main body of the thalamus creating a small knob visible during dissection 26 (C) Schematic drawing of an oblique section through median axis (also adapted from Le Gros Clark13 showing how the laminae fuse together at the anterior pole The afferent ganglion cell axons that form the optic tract (OT) penetrate through the anterior surface to reach their target relay cells in the laminae (D) Drawing of the most dorsal lamina-layer 6--separated from the rest of the LGN The geometric shape is a hollow half-cone so that right and left LGNs placed back-to-back form in effect a single cone Note also the position ofthe RTN shown here as a striped bar relative to lamina 6 The position of the striped bar shows that the RTN makes direct contact with lamina 6 at the edge ofthe lateral wing and also along the ventral edges (E - F) Schematic drawings adapted from Connolly and Van Essen24 that show how a 3-dimensional lamina-lamina 6--can be transformed into a 2-dimensional triangular figure lamina 6 is removed and its wings unfolded (E) creating a slightly asymmetric triangular figure (F) which is adjusted to an oblong shape (G) in order to superimshypose a grid matrix with minimal distortion The grid plots locations of TC cells that represent various isoelevations and isoazimuths in the VF locations derived from the experimental observations published by Malpeli and Baker 25 Note the relatively large amounts of laminar surface allocated to central vision (0 0

- 30 0) as compared

to peripheral vision (30 0 - 80 0)

characteristics (1) Spindle bursts must move simultaneously through both geniculate nuclei This pattern of movement is consistent with anatomical studies in primates that found axonal projections linking the right and left RTNs27-28 and with experimental studies in cats that found spindles appearing simultaneously in both right and left thalami 29 (2) Spindle waves must enter the ventral edges of the LGN first and move ventrodorsally in a highly coherent pattern-moving in effect as a standing wave This pattern of movement is consistent with in vitro experiments using sagittal slices from a ferret LGN where spindle waves originated spontaneously at the edge of a slice in an area which contains cells that represent peripheral vision then propagated toward that area of the slice containing cells that represent central vision in the ferret 3o

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 129

VF

PG BIlateral receptive lleJd of PVN YI(j Inward dmKooflality Adapled

0-- from Mortgr at at (1987)

V1

ibull t bull

RTN t t t t t t 1middot3 SECOlO BURSTS OF 7middot14 HZ SPiKES RECURRNG EVERY 3 10 SECONDS

To our knowledge the LGN is the only anatomical structure in the visual system that has the capacity of passively forcing a wave of excitation to flow across a conical surface thereby generating the sensation of a phosphene annulus that retains its symmetry as it shrinks in diameter The retina has a circular anatomy but it is not likely that the mechanical deformation of the retina would produce a wave that began simultaneously in all 3600 of the retinal rim nor that the symmetry of annular wave would be preserved as it flows inward toward the foveal region

The hypothesis presented here-that there is a structure in the visual system that imprints a conical shape on standing waves that move through it-explains

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 130

Figure 4 facing page Schematic drawing of contemporaneous events in selected regions of the visual processing hierarchy (A) The left and right RTNs fire spindle bursts simultaneously (B) The bursts pass through the right and left geniculate laminae as standing waves of depolarization entering from the ventral edges and moving ventrodorsally in parallel In order for the phosphene annulus to appear to be flowing at a constant rate the spindle wave flowing through the LCN must expand in width as it ascends ventrodorsally so that by the time the fill-in disk appears-when the center 30deg of the VF is covered by the phosphene annulus-the spindle wave must have expanded enough to activate relay cells in the most dorsal 50 of lamina 6 (C) Signals representing two complementary hemi-annuli are kept separate in the primary visual cortices (area VI) (D) Signals representing the two hemi-annuli are integrated into signals of a single annulus when they reach area PC in the posterior parietal cortex where the receptive fields of single parietal visual neurons have the capacity to register bilateral signals that exhibit opponent vector movement (that is signals converging from opposite directions along the central axes-as if an object were moving away from the viewer)46 Neurons in area PC also integrate wavelength (color) signals from the extrastriate visual pathway with signals about brightness motion and depth from the parietal visual pathway to compose a representation of an object in space-in this case of an annulus that appears to recede 32

the authors experience during MRI when he observed a continuous succession of receding annuli every 2 seconds in this view the energy of the electroshymagnetic bombardment when released during precessional relaxation flows through the geniculate laminae in the same way that the RTN spindle bursts do that is as a standing wave and thus the visual epiphenomenon is the same in both cases if the subject keeps the eyes focused straight ahead and the attention fixated In a study of phosphenes evoked by electricity in conjunction with hallucinogenic drugs Knoll Kugler Hofer and Lawder found that each subject sees specific kinds of phosphene at different frequencies and that these frequency-specific images are stable enough to be reproduced after six months31

They conclude that the tunability of the electrical stimulation frequenshycies within the EEG range to various definable phosphenes requires the existence of a resonance system One mechanism contributing to that resonance system may be the functional anatomy of the LGN

The colors of receding annuli as functions of geniculate laminar anatomy The colors of receding annuli phosphenes are consistent with the patterns of discharge spindle waves can be expected to stimulate as they move through

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 131

geniculate laminae As shown in Figure 5 the six laminae differ (1) in the types of wavelength signals relayed (2) in physical size and (3) in the area of the VF represented 24-25 Only 4 out of 6 laminae Cparvocellular layers 3shy6) contain TC cells that relay wavelength signals the other 2 laminae (magnocellular layers 1 and 2) do not encode wavelength Among parvocelshylular laminae only lamina 6 the longest and most dorsal layer contains TC cells that can represent the far periphery of the VF (from 800 to 50deg of isoeccenshytdeity) therefore when the spindle wave enters the peripheral VF only those wavelengths relayed by lamina 6 will participate in composing a cortical lightness record (See Zeki)32

I n lamina 6 ganglion cell axons arriving from the retina carry two kinds of wavelength signals (1) center-ON signals from medium-wavelength cones (M-cone center-ON) and long-wavelength cones (L-cone centershy

ON)33-35 Using the cone spectral sensitivity curves (adapted from Marks et al 36) we average the wavelengths that elicit maximal responses for M-cones (535 nanometers) and L-cones (520 nm) which yields a mean wavelength value of 550 nm In humans this wavelength generates a sensation of green or yellowshygreen the sensation observed by the author

As the spindle burst moves ventrodorsally it reaches the dorsal areas in the geniculate laminae which contain TC cells representing the central 0deg to 20deg of isoeccentrieity in the VE All 4 parvocellular laminae have TC cells which are potentially capable of representing this central region of vision but the authors observation that the color of the filling-in disk changed from green to blue implies that in the early years of phosphene induction the spindle wave must have remained close to the surface of the LGN stimulating only laminae 5 and 6 which generates a sensation of yellow-green When the fill-in disk was observed to change color from green to blue the spindle wave must have been rechanneled so that it began to penetrate below laminae 5 and 6 and to activate laminae 3 and 4 the only laminae that relay blue-sensitive signals (Sshycone center-ON signals)3 In light of the authors MRI experience it seems likely that a spindle wave requires a minimum of 2 seconds to reach the blueshysensitive cells of laminae 4 therefore during MRI when the receding annuli disappeared after 2 seconds half the normal duration the fill-disk had a green color even though it had long since change to blue in other induction settings with a 4-second trajectory

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 132

A REPRESENTATION OF THE VISUAL FIELD IN EACH LAMINA

orooqUtftc O-u OCIJ1SALfIOLI (I01flAj

0

10

20

30

40 n50 Of

60

70

20 loO 1Mgr_ II~ o UIpoundAS65 mn1MY-o actlvncL ~~~r

Jll-COMcetlImiddot~

II LAYERSU 3 GatQYancetl~ (1) ucon ceom-oyenF (2)l~cen()FF 3) ~ cenloH

II~ cng1loqctWIIIfNla

iICINe -- (t81Otdb1t1d~OH (2)~

80

B CONE SPECTRAL SENSITIVITY CURVES

S-COHS

WAVIlLllNG1llS OF UGHT IH NANOMllTERS (NM)

Figure 5 Phosphene color as a function of ganglion cell distribution in parvocellular laminae (Aj Schematic drawing ofthe proportion ofthe VF represented in each laminae The proportions shown here are based on the work of Connolly and Van Essen24 The

far periphery of vision (50 0 to 80 0 of isoeccentricity) is represented in only two laminae-laminae 1 and 6-and of these two only lamina 6 is a parvocelLular lamina capable ofencoding wavelength signals Therefore only those wavelengths relayed by lamina 6 will participate in forming a cortical lighmess record for the far periphery of the VP (B) Cone spectral sensitivity curves (adapted from Marks et al)36 Using these cone sensitivity curves we can estimate the sensation stimulated by a spindle wave moving through lamina 6 by averaging the wavelengths that elicit maximal responses for M-cones (535 nanomeshyters) and L-cones (520 nm) which yields a mean wavelength value of550 nm In humans this generates a sensation of green or yellow-green the sensation observed by the author when the receding annulus enters at the far periphery of the VP For a calculation of the cortical lightness record when a spindle wave moves through 20deg to 0deg ofthe VF stimulating all 4 parvocelfular laminae see the text and Figure 6

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 133

Once the spindle wave penetrates to laminae 3 and 4 it may activate all 4 parvocellular laminae stimulating TC cells to send contradictory wavelength signals for the same retinotopic location the signals sent from laminae 4 and 3 will encode blue light (S-cone center-ON plus M-cone center-OFF and Lshycone center-OFF) while the signals sent from laminae 5 and 6 encode yellowshygreen light (M-cone center-ON plus L-cone center-ON) This kind of contrashydiction does not occur in normal retina-based perception where light energy striking the retina is structured by the retinas center-surround and colorshyopponent organization to encode only one set of wavelength signals for each spatial locus 32 In Figure 6 we estimate the cortical lightness record that results when contradictory wavelength signals compete to be represented in consciousshyness Our calculations suggest that the outcome will be a mean wavelength which in humans elicits a dark blue or violet sensation

PART II AMORPHOUS PHOSPHENES amp THALAMIC DELTA ACTMTY

M echanisms controlling the transition from spindle bursts to delta activity In the consensus scenario for the generation of NREMS16-20 we noted that the RTN shifts to firing spindle bursts

when polarization of thalamic cell membranes drops to V m = - 60 mV At the same time cortical cells begin oscillating with a synchronous slow rhythm laquo 1 Hz) Both processes further decrease the Vm of TC cell membranes When Vm = - 75 mY TC cells begin to generate their own intrinsic calcium currents which also decreases V m At V m = - 90 mV RTN neurons stop firing spindle bursts At the same time the TC cells begin firing low-threshold calcium spikes in alternation with after-hyperpolarizations (LTS-AHP) Because sensory relay neurons in the LGN are not linked to one another by locally projecting axons the firing of one TC cell does not excite its neighbor However a lack of local connectivity does not mean that TC cells occupying the same laminae release their AHP-LTS calcium spikes in a random distribshyution rather spikes are released simultaneously by groups of cells in synchrony with the advent of the cortical slow wave In effect the distribution of LTSshyAHP spikes firing in the LGN is determined by the spatial propagation of the cortical slow wave Thus the delta wave (1 to 4 Hz) activity detected by cortical EEG during NREMS is a product of the interaction between the AHP-LTS calcium spikes released by TC cells and the cortical slow rhythm

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 134

CORTICAL PROCESSING OF CONTRADICTORY

WAVELENGTH SIGNALS

KEY _ Cells firing

cJ Cononol firing

Assume that as a spind6e wave moves through the LGNlt fires simultaneously aU the TC cells that represent a particular reUnoshytopic locus (x y) in each of the six laminae As a result cortical cells engaged In the higher level processing of visual signals will receive more wavelength signals representing retina locus (x y) than are generated by normal perception laquo and some of these afferent wavelength signals may contradict other signals arriving simultaneously

CORTICAL LIGHTNESS RECORD SlgnalSell

Intemal contradictions not congruent wilt pre

SmiddotON eristing neuron neta

s bullbull M-ON LmiddotON

3 bullbull M-OFF + L-OFF

a-ON 12

ROD-ON

No Internal eonlradlemiddot

--------1I =~8b~~~~~~~t signals

3+4

~ --OFF Excludes 6 Of 7 $J9n18

1+2 B-ON I

IWmiddotHmiddotI Signal Sell

1111111 No Intern1 conlrfldlcshy lion

Exelvdta 4 out of 7 efshy

bullbullbull bullbullbull ferant signals

No Intern1 contradic_ tionnee S-ON BshyOH and ROO-ON can all be coacllve at low lImlnance levels nef Ihe rod-eone break

ExchJde$ only 2 Ollt of 7 afferent signals

Figure 6 Selection of competing wavelength signals based on neuronal group selection This thought experiment is based on Edelman sconcept ofneuronal group selection 73 We assume that all possible combinations ofsignals will form sets and that all signal-sets will compete to make the most efficient match with pre-existing neuromd networks that have been forged over years ofnorma reti1U1-based perception We also assume that pre-existing neural networks are most likely to expedite those sets that satisfY 2 criteriI (J) the signals in a set do not contradict each other and (2) fower signals are excluded than in the other sets that satisfY the first criterion In our analysis Set 4 wins the competition because it does not contain internal contradictions and excludes fower signals (2 out of 7) than Set 3 excludes (4 out of7) It is not an internal contradiction that Set 4 contains both rods and cone Signtlls in normal retina-based perception when luminance levels approach the rod-cone break S-cone center-ON receptors send signas as do rod receptors and there is even evidence that rod activity may actually drive S-cone activity even after luminance levels foIl below the rod-cone break74 To calculate the cortical lightness record for Set 4 we average the wavelength that elicits maximal responses foom rods (511 nm) and for Sshycones (430 nm) which yields a mean wavelength of 470 nm which in humans results in a dark-blue or violet sensation

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 135

The cortical slow rhythm is an example of a generic pattern of neuronal excitashytion that occurs in large networks of neurons linked by local projections A recent experiment by Maeda Robinson and Kwana38 shows that networks of locally-connected neurons spontaneously generate periodic synchronized bursts of calcium transients that propagate across the network in an expanding spatial wave a pattern that represents a stable mode of firing towards which these neuronal networks relax following perturbations for example by electronic stimulation or by drugs Understanding the characteristics of these waves is an important prerequisite to understanding the mechanisms that produce the amorphous phosphene images as a visual epiphenomenon

To study the spontaneous periodic synchronized bursts the researchers prepared cultures of dissociated cortical neurons and allowed them to mature for several days in vitro (DIV) After 3 to 4 DIV when concenshy

trations of extracellular magnesium were low electrodes began to detect spontaneous synchronized bursts of low frequency calcium transients (between 01 and 1 Hz) that originated in different locations on the sheet every 10 to 20 seconds and spread across the sheet of cells at a relatively slow speed averaging 50 mmsecond The researchers could not predict where a wave would originate or where it would expand rather the initiation and expansion of waves was generated by spatial and temporal summation of a continuous random background of synaptic inputs including miniature spontaneous synaptic events but the pattern was not random since waves propagated sequentially from electrode to electrode as each local group of neurons charges up its neighboring nontefractory areas rather than in a random sequence of regions38

The excitability of the cells in the sheet determines the probability first that there will be a synchronous burst and second that it will spread in a particshyular direction Cells become more excitable as the cultures mature which means the refractory intervals between successive bursts were much shorter in mature cultures (gt 30 DIV) than in early cultures laquo 7 DIV) Some cells became so insensitive to inhibition that they continued to fire bursts even when extracellular concentrations of magnesium were relatively high Finally there were refractory periods of 5 to 10 seconds during which no bursts occurred even when an electrical stimulus was applied This refractory interval for cultured networks is slightly longer than the refractory interval observed of the cortical slow wave in vivo which 25 to 4 seconds 18- 19

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 136

Based on the observations about cortical slow waves we can predict that phosphenes generated as epiphenomena of delta wave activity will present the following signal characteristics (1) signals that appear at unpredictable locations in the VF (2) signals that expand and diverge asymmetrically following unpredictable trajectories which may encompass large areas of the VF (3) signals that move relatively slowly (50 mmsec) (4) signals that recur with a period of 2 to 4 seconds reflecting entrainment by the cortical slow wave (5) signals that do not terminate automatically after a predictable number of cycles

The spatial patterns of phosphene mists and thalamic delta waves are similar The spatiotemporal characteristics of amorphous phosphenes match the pattern of wave propagation associated with periodic spontashy

neous synchronized bursts in large neuron networks the amorphous phosphenes enter the visual field at unpredictable locations expand and diverge asymmetrically with a slow steady rate of flow follow trajectories that are unpredictable and exhibit a refractory interval The amorphous mists do appear to have a periodicity although the author is unable to sustain the vision while also counting the seconds therefore he is unable to determine if it compares to the period of the cortical slow wave (25 to 4 seconds) but his impression is that it feels roughly the same as as with receding annuli which recur at 5 seconds Also the refractory interval feels as if it decreases as the induction session is extended These similarities suggest that the amorphous phosphenes are generated by stage 2 NREMS delta wave activity which is an activity governed by the reverberation of the cortical slow wave in thalamoshycorticothalamic circuits The cortical slow wave is referred to the LGN where it modulates the firing of visual relay cells in the laminae and since relay cells do not have local dendritic connections the expansion of a wave of depolarshyizations moving from one relay cell to the next across in the laminar surface will mirror at least in part the expansion of the cortical wave that is spreading contemporaneously through locally-connected cortical cells

PART III RETENTION OF CONSCIOUSNESS

In a normal transition to NREMS the volley of synchronous spindle bursts that marks the onset of stage 2 NREMS overwhelms the normal firing pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 137

of thalamocortical cells preventing their relay of afferent sensory signals and inducing a loss of consciousness21 But the loss of consciousness cannot be timed precisely using cortical EEG the thalamus is too remote for the onset of spindling to be reliably detected by scalp electrodes39 In experiments with cats where electrodes could be implanted in the thalamus researchers found that spindling often reached peak levels of activity in the thalamus-a level of activity consonant with stage 2 NREMS-at a time when the cortical EEG was still showing intermittent desynchronizations a pattern characteristic of the drowsy stage 1 transition not a fully-established stage 2 NREMS episode4o

In other words there is a short period of time in which the synchronous rhythms of stage 2 NREMS are installed in the thalamus but not in the cortex where cortical neurons continue to depolarize in response to afferent sensory signals

T his finding suggests a possible explanation for the authors ability to retain consciousness while spindle bursts are sweeping through the LGN if he is able to extend the duration of this time lag between

the onset of spindling in the thalamus and spindling in the cortex if he is able to stimulate the visual cortices in such a way that they continue to depolarize then he may be able to keep on processing visual signals-to remain visually aware-even after the non-visual thalamus and non-visual cortex become entrained by synchronous sleep rhythms The authors induction technique includes several behaviors which are known to enhance the responsiveness of visual neurons-eye movements attentive fixation and an attitude of expectancy

Effects of eye movements and attention on the LGN Sustained convergence causes periorbital proprioceptors to send excitatory feedback directly to the LGN41 Also convergence further enhances the excitability of geniculate cells by stimulating the superior collicus (SC) which sends its own excitatory signals to the LGN42-43 These signals from the SC are known to selectively enhance the excitability of visual relay cells that represent the periphery of vision44 We know in the authors case that the SC is being stimulated because he is able to keep on fixating an ability which would normally be lost during the transishytion to NREMS45 The ability to fixate can be retained however if the SC is stimulated (even if stimulated during NREMS)46

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 138

Effects of eye movement attention and expectancy on the primary visual cortex The PET study of mental imagery by Kosslyn et al 3 showed that even a baseline resting state of relaxed immobile expectancy can generate signifishycant increases in neuronal activity in the primary visual cortices Further increases can be induced by sustained eye movements

A sustained convergence will release a stream of ponto-geniculo-occipital (PGO) waves These PGO waves called eye movement potentials or EMPs last only as long as the eye movement1747 whereas the PGO waves associated with rapid-eye-movement sleep (REMS) fire continually for the duration of the REMS episode Both REMS-related PGO waves and EMPs have the same desynchronizing effect on the visual pathways they move through the LGN depolarizing the thalamocortical cells which relay the signals to cortical neurons The responsivity of neurons in the primary visual cortices is enhanced by the stimulation of PGO waves 1747-49 If the passage of EMPs causes the genicushylate relay cells and their cortical targets to depolarize regularly then a volley of 4 spindle bursts moving through the same pathways will register as just another series of depolarizations in effect the spindle bursts are processed by the visual system as if they were sensory signals sent from the retina rather than an event stimulated by endogenous mechanisms

T he impact of eye movements and ftxation on the parietal visual cortex Convergence and attentive fixation will also enhance the responsiveness of light-sensitive parietal visual neurons (PVNs) in area PG of the

posterior parietal cortex 50 In experiments where monkeys are trained to fix their attention on a screen-and to keep on fixating even if no targets appearshythe excitability of these light-sensitive PVNs increases by as much as 350 51

52-53Responsiveness is also facilitated by the angle of gaze Also area PG is the first region in the visual pathways containing individual neurons with the capacity to respond to large bilateral stimuli moving in opposite directions along the central meridians of vision (opponent vector motion) 853-55 Facilitation of PVNs in area PG has the effect of sensitizing the subject to bilateral opponent vector motion and this is especially true if the movement appears in the periphery of the VE 8

Intracortical ampliftcation and feedback to the LGN When PGO waves and signals from the SC arrive in the primary visual cortex they may be relatively weak however weak signals can be amplified by reverberating in large networks

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 139

of cortical cells linked by local projection 56 There are nine times as many excitatory links among cortical cells as there are projections from the visual cortex to the LGN an imbalance which suggests leads Suarez Koch and Douglas to propose that geniculate input provides only a minor fraction of the excitatory input the majority originating in neighboring and recurrently connected cortical cells57 If the excitabiliry of cortical neurons is slightly higher than normal then this process of amplification may continue even after the LGN signals that initiated the reverberation are no longer being transmitted by the LGN ( a hysteretic mode of operation) 57

Feedback from hyperexcited cortical neurons will stream back to the LGN via corticogeniculate projections which outnumber geniculocortical projections ten-to-one One effect of this feedback is that the LGN is

able to absorb large amounts of information flowing back from the cortex 58

As signals reverberate back and forth in thalamocorticothalamic circuits a matching process takes place those geniculate relay cells that fire in patterns consistent with the firing patterns of active cortical cells will have their responshysivity enhanced while those geniculate cells that fire in patterns not consistent with cortical cells will be suppressed 59

Preservation of consciousness by selective facilitation of the visual pathways By combining all of the facilitatory effects produced by the authors eye movements and attentive fixation-(l) stimulation of the LGN by feedback from periorbital proprioception both directly and indirectly via the SC (2) the release of PGO waves (EMPs) that facilitate neurons in the LGN and primary visual cortex as they pass (3) the facilitation of the primary visual cortex by a state of relaxed immobile expectancy (4) attentive fixation and angle of gaze that facilitate PVNs in area PG (5) intracortical amplification of signals received from the LGN and (6) corticogeniculate feedback that stimulates the LGN-we delineate a circuit of enhanced excitability that extends from the LGN through the post-geniculate visual heirarchy to area PG where signals are integrated into representations of objects

The hyperexcitability of neurons all along the post-geniculate visual pathways creates conditions in the visual cortices which are similar to those present during EEG-desynchronized states of waking and REMS Therefore neurons in the visual pathways are too excitable to be entrained by synchronous bursting

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 140

patterns when spindle waves move through them instead the spindle bursts stimulate visual neurons to depolarize and then recover as happens in response to afferent sensory signals during waking states It is important to note that for this to occur none of the constituent neuron assemblies is required to perform an abnormal operation the abnormality is a function of the authors intent to activate contemporaneously neuron assemblies that would not normally be co-activated

PART IV HYPNOTIC ANALGESIA

Manipulation of spatial attention as a method for alleviating pain sensations In a theoretical article on the neurophysiology of hypnosis Crawford and Gruzelier60 propose that variations in hypnotizability are function of variability in the efficiency of the frontolimbic (anterior) attentional system in humans high-hypnotizables are better able to sustain focused attention on a task and to ignore extraneous stimuli than are low-hypnotizables

I na related empirical study that compares the use of attention by subjects with high versus low hypnotizability Crawford Brown and Moon61 report that highly hypnotizable persons continue to show physiological reactivity

while cognitively not perceiving the painful stimuli Through disattentional processes they can dissociate themselves from the awareness of pain The authors phosphene induction behaviors-and the cutaneous analgesia he experishyences-appear to involve the same kind of behaviors that is a mobilization of frontolimbic attention used to withdraw attention from external stimuli and to concentrate it on internally-generated phosphene images This suggests the hypothesis that the mechanisms that generate phosphenes might also produce hypnotic analgesia There are several ways that visual signals and pain signals might interact to produce this analgesia

Competition between pain and vision signals for limbic registration The fully-developed sensation of pain requires integration of rwo kinds of informashytion Signals that encode the location and intensity of a noxious stimulus (nociceptive signals) are relayed via the thalamus to the somatosensory cortices which registers only the sensory-discriminative aspects of pain perception62 before reaching consciousness the nociceptive signals must be sent to the limbic

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 141

system where they are linked with signals from long-term memory that encode the affective significance the stimulus has acquired for that individual Studies of brain metabolism show this linking of somatosensory information with limbic associations takes place in the anterior cingulate (CG) and anterior insula62-64

PET studies also show that the anterior CG is activated when subjects shift their spatial attention in response to expectations as to where

66stimuli will next appear65- This is precisely what takes place during the state of immobile expectancy that induces phosphenes Since visual signals and nociceptive signals both require limbic enhancement which is only possible if they get access to the anterior CG there might be conditions in which the two types of afferent sensory signals have to compete for that access In a theoretical article on the mechanisms of attention Posner and Rothbart67

propose that visual signals can interfere with nociceptive signals by blocking access to the anterior CG As behavioral evidence they cite studies showing that when young infants make distress calls they can be distracted by the presentation of a new visual stimulus We have shown the evidence of such control at about three months Orienting to visual events can be employed to quiet or calm negative vocalizations However the distress appears to be maintained and reappears when the infants attention to the stimulus is reduced Caregivers also report the use or visual orienting to block overt manifestations of distress at about this age 67

The effects of disattention on the somatosensory cortices If there is a competition between visual signals and nociceptive signals for access to the anterior CG it is likely that the competition will be affected by the relative volume of signals received A recent study suggests that focusing attention on internally-generated visual stimuli may reduce the number of nociceptive signals relayed by the somatosensory cortices Drevets Burton Videen Snyder Simpson and Raichle68 have shown that the mere anticipation of a touch at a specific cutaneous site increases the flow of blood to those cortical somatosenshysory neurons that are linked with that site where touch is expected and decreases the flow of blood to neurons linked with sites where touch is not expected In this experiment the researchers designated touch as the behaviorally significant sensory stimulus but their findings suggest that the outcome could be reversed if the instructions were reversed if subjects were

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page J42

instructed to direct attention away from a cutaneous site where a noxious stimulus was being applied if they were instructed to relax close their eyes and concentrate on the play of phosphenes in the visual field as the behaviorally significant sensory stimulus then it would be reasonable to expect that the flow of blood would decrease to the somatosensory neurons linked with the cutaneous stimulus and that the flow of blood would increase to the visual cortices The decrease in blood flow to somatosensory neurons implies less neuronal activity which implies that fewer signals are being sent forward to the anterior CG than would have been sent if instead the subject were treating the touch as the behaviorally significant sensory stimulus If fewer pain signals arrive at the anterior it is reasonable to infer that the conscious experience of pain will be muted by the diversion of attention to internal visual stimuli

Differential impact of sleep rhythms in the visual and nonvisual thalamus There is another mechanism that might also contribute to the analgesic effect of inducing sleep rhythms PET studies show that

the thalamus is involved in the relay of nociceptive signals to the cortex63 although some confusion remains about which kinds of signals are relayed by which subregions in the thalamus62 One thalamic site clearly identified by anatomical studies as a relay for nociceptive signals is the ventroposterior lateral nucleus (VPL)69 If synchronous sleep rhythms are active in the thalamus we can reasonably expect that the VPL will itself be entrained by synchronous oscillations and that it will relay the sleep rhythms to somatosensory cortices Relay neurons in the VPL are not stimulated by feedback from eye movements and fixation as are relay neurons in the LGN which suggests that sleep rhythms may impede the relay of nociceptive signals via the VPL but not the relay of visual signals via the LGN

Brain waves associated with anesthesia and NREMS The hypothesis presented here-that consciousness can be preserved despite the presence of NREMS activity-is consistent with a recent report that the kinds of fast brain waves which are normally associated with conscious states are also present during NREMS and anesthesia two states which were thought to involve minimal brain activityJo Another recent study found that there is a close resemblance between the slow brain waves that appear during NREMS and those that appear during certain types of anesthesia71

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 143

bull bull bull

CONCLUSION

In this paper we have presented evidence supporting the hypothesis that phosphene images can be generated as an epiphenomena of thalamic spindle bursts and delta wave activity normally associated with NREMS The prereqshyuisites for inducing these sleep rhythm phosphenes are relaxed immobile expectancy sustained convergence and attentive fixation of an undifferentiated visual field Our hypothesis provides a necessary and sufficient explanation for the authors induction of phosphenes and perhaps also for the generation of phosphenes reported to appear spontaneously during the drowsy transition to sleep (hypnagogic states) during sensory deprivation or during certain kinds of prayer or meditation all of which involve a similar state of relaxed immobile expectancyJ2

CORRESPONDENCE Philip T Nicholson bull 52 Norfolk Road bull Chestnut Hill MA 02167

REFERENCES amp NOTES

1 M 1 Posner Modulation by Instruction Nature 373 (1995) pp 198-199 2 J Reissenweber E David amp M pfotenhauer Investigations of Psychological Aspects of

the Perception of Magnetophosphenes and Electrophosphenes Biomedizinische Tecknik 373 (1992) pp 42-45

3 S M Kosslyn W L Thompson 1 J Kim amp N M Alpert Topographical Representations of Mental Images in Primary Visual Cortex Nature 378 (I995) pp 496-498

4 P E Roland amp B Gulyas Visual Memory Visual Imagery and Visual Recognition of Large Field Patterns by the Human Brain Functional Anatomy by Positron Emission Tomography Cerebral Cortex 51 (1995) pp 79-93

5 H Benson The Relaxation Response (Morrow New York NY 1975) 6 ] H Schultz amp W Luthe Autogenic Training a Physiological Approach to Psychotherapy

(Grune amp Stratton New York NY 1969) 7 E Jacobson Progressive Relaxation (University of Chicago Press Chicago IL 1938) 8 M A Steinmetz BC Motter C] DuffY amp V B Mountcastle Functional Properties

of Parietal Visual Neurons Radial Organization of Directionalities Within the Visual Field Journal ofNeuroscience 71 (1987) pp 177-191

9 R R Edelman Magnetic Resonance Imaging of the Nervous System Discussions in Neuroscience 71 Elsevier Science Amsterdam (I990) also J H Newhouse amp ] I Wiener Understanding MRI 1st Ed (Little Brown Boston MA 1991)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 144

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

VF

PG BIlateral receptive lleJd of PVN YI(j Inward dmKooflality Adapled

0-- from Mortgr at at (1987)

V1

ibull t bull

RTN t t t t t t 1middot3 SECOlO BURSTS OF 7middot14 HZ SPiKES RECURRNG EVERY 3 10 SECONDS

To our knowledge the LGN is the only anatomical structure in the visual system that has the capacity of passively forcing a wave of excitation to flow across a conical surface thereby generating the sensation of a phosphene annulus that retains its symmetry as it shrinks in diameter The retina has a circular anatomy but it is not likely that the mechanical deformation of the retina would produce a wave that began simultaneously in all 3600 of the retinal rim nor that the symmetry of annular wave would be preserved as it flows inward toward the foveal region

The hypothesis presented here-that there is a structure in the visual system that imprints a conical shape on standing waves that move through it-explains

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 130

Figure 4 facing page Schematic drawing of contemporaneous events in selected regions of the visual processing hierarchy (A) The left and right RTNs fire spindle bursts simultaneously (B) The bursts pass through the right and left geniculate laminae as standing waves of depolarization entering from the ventral edges and moving ventrodorsally in parallel In order for the phosphene annulus to appear to be flowing at a constant rate the spindle wave flowing through the LCN must expand in width as it ascends ventrodorsally so that by the time the fill-in disk appears-when the center 30deg of the VF is covered by the phosphene annulus-the spindle wave must have expanded enough to activate relay cells in the most dorsal 50 of lamina 6 (C) Signals representing two complementary hemi-annuli are kept separate in the primary visual cortices (area VI) (D) Signals representing the two hemi-annuli are integrated into signals of a single annulus when they reach area PC in the posterior parietal cortex where the receptive fields of single parietal visual neurons have the capacity to register bilateral signals that exhibit opponent vector movement (that is signals converging from opposite directions along the central axes-as if an object were moving away from the viewer)46 Neurons in area PC also integrate wavelength (color) signals from the extrastriate visual pathway with signals about brightness motion and depth from the parietal visual pathway to compose a representation of an object in space-in this case of an annulus that appears to recede 32

the authors experience during MRI when he observed a continuous succession of receding annuli every 2 seconds in this view the energy of the electroshymagnetic bombardment when released during precessional relaxation flows through the geniculate laminae in the same way that the RTN spindle bursts do that is as a standing wave and thus the visual epiphenomenon is the same in both cases if the subject keeps the eyes focused straight ahead and the attention fixated In a study of phosphenes evoked by electricity in conjunction with hallucinogenic drugs Knoll Kugler Hofer and Lawder found that each subject sees specific kinds of phosphene at different frequencies and that these frequency-specific images are stable enough to be reproduced after six months31

They conclude that the tunability of the electrical stimulation frequenshycies within the EEG range to various definable phosphenes requires the existence of a resonance system One mechanism contributing to that resonance system may be the functional anatomy of the LGN

The colors of receding annuli as functions of geniculate laminar anatomy The colors of receding annuli phosphenes are consistent with the patterns of discharge spindle waves can be expected to stimulate as they move through

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 131

geniculate laminae As shown in Figure 5 the six laminae differ (1) in the types of wavelength signals relayed (2) in physical size and (3) in the area of the VF represented 24-25 Only 4 out of 6 laminae Cparvocellular layers 3shy6) contain TC cells that relay wavelength signals the other 2 laminae (magnocellular layers 1 and 2) do not encode wavelength Among parvocelshylular laminae only lamina 6 the longest and most dorsal layer contains TC cells that can represent the far periphery of the VF (from 800 to 50deg of isoeccenshytdeity) therefore when the spindle wave enters the peripheral VF only those wavelengths relayed by lamina 6 will participate in composing a cortical lightness record (See Zeki)32

I n lamina 6 ganglion cell axons arriving from the retina carry two kinds of wavelength signals (1) center-ON signals from medium-wavelength cones (M-cone center-ON) and long-wavelength cones (L-cone centershy

ON)33-35 Using the cone spectral sensitivity curves (adapted from Marks et al 36) we average the wavelengths that elicit maximal responses for M-cones (535 nanometers) and L-cones (520 nm) which yields a mean wavelength value of 550 nm In humans this wavelength generates a sensation of green or yellowshygreen the sensation observed by the author

As the spindle burst moves ventrodorsally it reaches the dorsal areas in the geniculate laminae which contain TC cells representing the central 0deg to 20deg of isoeccentrieity in the VE All 4 parvocellular laminae have TC cells which are potentially capable of representing this central region of vision but the authors observation that the color of the filling-in disk changed from green to blue implies that in the early years of phosphene induction the spindle wave must have remained close to the surface of the LGN stimulating only laminae 5 and 6 which generates a sensation of yellow-green When the fill-in disk was observed to change color from green to blue the spindle wave must have been rechanneled so that it began to penetrate below laminae 5 and 6 and to activate laminae 3 and 4 the only laminae that relay blue-sensitive signals (Sshycone center-ON signals)3 In light of the authors MRI experience it seems likely that a spindle wave requires a minimum of 2 seconds to reach the blueshysensitive cells of laminae 4 therefore during MRI when the receding annuli disappeared after 2 seconds half the normal duration the fill-disk had a green color even though it had long since change to blue in other induction settings with a 4-second trajectory

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 132

A REPRESENTATION OF THE VISUAL FIELD IN EACH LAMINA

orooqUtftc O-u OCIJ1SALfIOLI (I01flAj

0

10

20

30

40 n50 Of

60

70

20 loO 1Mgr_ II~ o UIpoundAS65 mn1MY-o actlvncL ~~~r

Jll-COMcetlImiddot~

II LAYERSU 3 GatQYancetl~ (1) ucon ceom-oyenF (2)l~cen()FF 3) ~ cenloH

II~ cng1loqctWIIIfNla

iICINe -- (t81Otdb1t1d~OH (2)~

80

B CONE SPECTRAL SENSITIVITY CURVES

S-COHS

WAVIlLllNG1llS OF UGHT IH NANOMllTERS (NM)

Figure 5 Phosphene color as a function of ganglion cell distribution in parvocellular laminae (Aj Schematic drawing ofthe proportion ofthe VF represented in each laminae The proportions shown here are based on the work of Connolly and Van Essen24 The

far periphery of vision (50 0 to 80 0 of isoeccentricity) is represented in only two laminae-laminae 1 and 6-and of these two only lamina 6 is a parvocelLular lamina capable ofencoding wavelength signals Therefore only those wavelengths relayed by lamina 6 will participate in forming a cortical lighmess record for the far periphery of the VP (B) Cone spectral sensitivity curves (adapted from Marks et al)36 Using these cone sensitivity curves we can estimate the sensation stimulated by a spindle wave moving through lamina 6 by averaging the wavelengths that elicit maximal responses for M-cones (535 nanomeshyters) and L-cones (520 nm) which yields a mean wavelength value of550 nm In humans this generates a sensation of green or yellow-green the sensation observed by the author when the receding annulus enters at the far periphery of the VP For a calculation of the cortical lightness record when a spindle wave moves through 20deg to 0deg ofthe VF stimulating all 4 parvocelfular laminae see the text and Figure 6

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 133

Once the spindle wave penetrates to laminae 3 and 4 it may activate all 4 parvocellular laminae stimulating TC cells to send contradictory wavelength signals for the same retinotopic location the signals sent from laminae 4 and 3 will encode blue light (S-cone center-ON plus M-cone center-OFF and Lshycone center-OFF) while the signals sent from laminae 5 and 6 encode yellowshygreen light (M-cone center-ON plus L-cone center-ON) This kind of contrashydiction does not occur in normal retina-based perception where light energy striking the retina is structured by the retinas center-surround and colorshyopponent organization to encode only one set of wavelength signals for each spatial locus 32 In Figure 6 we estimate the cortical lightness record that results when contradictory wavelength signals compete to be represented in consciousshyness Our calculations suggest that the outcome will be a mean wavelength which in humans elicits a dark blue or violet sensation

PART II AMORPHOUS PHOSPHENES amp THALAMIC DELTA ACTMTY

M echanisms controlling the transition from spindle bursts to delta activity In the consensus scenario for the generation of NREMS16-20 we noted that the RTN shifts to firing spindle bursts

when polarization of thalamic cell membranes drops to V m = - 60 mV At the same time cortical cells begin oscillating with a synchronous slow rhythm laquo 1 Hz) Both processes further decrease the Vm of TC cell membranes When Vm = - 75 mY TC cells begin to generate their own intrinsic calcium currents which also decreases V m At V m = - 90 mV RTN neurons stop firing spindle bursts At the same time the TC cells begin firing low-threshold calcium spikes in alternation with after-hyperpolarizations (LTS-AHP) Because sensory relay neurons in the LGN are not linked to one another by locally projecting axons the firing of one TC cell does not excite its neighbor However a lack of local connectivity does not mean that TC cells occupying the same laminae release their AHP-LTS calcium spikes in a random distribshyution rather spikes are released simultaneously by groups of cells in synchrony with the advent of the cortical slow wave In effect the distribution of LTSshyAHP spikes firing in the LGN is determined by the spatial propagation of the cortical slow wave Thus the delta wave (1 to 4 Hz) activity detected by cortical EEG during NREMS is a product of the interaction between the AHP-LTS calcium spikes released by TC cells and the cortical slow rhythm

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 134

CORTICAL PROCESSING OF CONTRADICTORY

WAVELENGTH SIGNALS

KEY _ Cells firing

cJ Cononol firing

Assume that as a spind6e wave moves through the LGNlt fires simultaneously aU the TC cells that represent a particular reUnoshytopic locus (x y) in each of the six laminae As a result cortical cells engaged In the higher level processing of visual signals will receive more wavelength signals representing retina locus (x y) than are generated by normal perception laquo and some of these afferent wavelength signals may contradict other signals arriving simultaneously

CORTICAL LIGHTNESS RECORD SlgnalSell

Intemal contradictions not congruent wilt pre

SmiddotON eristing neuron neta

s bullbull M-ON LmiddotON

3 bullbull M-OFF + L-OFF

a-ON 12

ROD-ON

No Internal eonlradlemiddot

--------1I =~8b~~~~~~~t signals

3+4

~ --OFF Excludes 6 Of 7 $J9n18

1+2 B-ON I

IWmiddotHmiddotI Signal Sell

1111111 No Intern1 conlrfldlcshy lion

Exelvdta 4 out of 7 efshy

bullbullbull bullbullbull ferant signals

No Intern1 contradic_ tionnee S-ON BshyOH and ROO-ON can all be coacllve at low lImlnance levels nef Ihe rod-eone break

ExchJde$ only 2 Ollt of 7 afferent signals

Figure 6 Selection of competing wavelength signals based on neuronal group selection This thought experiment is based on Edelman sconcept ofneuronal group selection 73 We assume that all possible combinations ofsignals will form sets and that all signal-sets will compete to make the most efficient match with pre-existing neuromd networks that have been forged over years ofnorma reti1U1-based perception We also assume that pre-existing neural networks are most likely to expedite those sets that satisfY 2 criteriI (J) the signals in a set do not contradict each other and (2) fower signals are excluded than in the other sets that satisfY the first criterion In our analysis Set 4 wins the competition because it does not contain internal contradictions and excludes fower signals (2 out of 7) than Set 3 excludes (4 out of7) It is not an internal contradiction that Set 4 contains both rods and cone Signtlls in normal retina-based perception when luminance levels approach the rod-cone break S-cone center-ON receptors send signas as do rod receptors and there is even evidence that rod activity may actually drive S-cone activity even after luminance levels foIl below the rod-cone break74 To calculate the cortical lightness record for Set 4 we average the wavelength that elicits maximal responses foom rods (511 nm) and for Sshycones (430 nm) which yields a mean wavelength of 470 nm which in humans results in a dark-blue or violet sensation

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 135

The cortical slow rhythm is an example of a generic pattern of neuronal excitashytion that occurs in large networks of neurons linked by local projections A recent experiment by Maeda Robinson and Kwana38 shows that networks of locally-connected neurons spontaneously generate periodic synchronized bursts of calcium transients that propagate across the network in an expanding spatial wave a pattern that represents a stable mode of firing towards which these neuronal networks relax following perturbations for example by electronic stimulation or by drugs Understanding the characteristics of these waves is an important prerequisite to understanding the mechanisms that produce the amorphous phosphene images as a visual epiphenomenon

To study the spontaneous periodic synchronized bursts the researchers prepared cultures of dissociated cortical neurons and allowed them to mature for several days in vitro (DIV) After 3 to 4 DIV when concenshy

trations of extracellular magnesium were low electrodes began to detect spontaneous synchronized bursts of low frequency calcium transients (between 01 and 1 Hz) that originated in different locations on the sheet every 10 to 20 seconds and spread across the sheet of cells at a relatively slow speed averaging 50 mmsecond The researchers could not predict where a wave would originate or where it would expand rather the initiation and expansion of waves was generated by spatial and temporal summation of a continuous random background of synaptic inputs including miniature spontaneous synaptic events but the pattern was not random since waves propagated sequentially from electrode to electrode as each local group of neurons charges up its neighboring nontefractory areas rather than in a random sequence of regions38

The excitability of the cells in the sheet determines the probability first that there will be a synchronous burst and second that it will spread in a particshyular direction Cells become more excitable as the cultures mature which means the refractory intervals between successive bursts were much shorter in mature cultures (gt 30 DIV) than in early cultures laquo 7 DIV) Some cells became so insensitive to inhibition that they continued to fire bursts even when extracellular concentrations of magnesium were relatively high Finally there were refractory periods of 5 to 10 seconds during which no bursts occurred even when an electrical stimulus was applied This refractory interval for cultured networks is slightly longer than the refractory interval observed of the cortical slow wave in vivo which 25 to 4 seconds 18- 19

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 136

Based on the observations about cortical slow waves we can predict that phosphenes generated as epiphenomena of delta wave activity will present the following signal characteristics (1) signals that appear at unpredictable locations in the VF (2) signals that expand and diverge asymmetrically following unpredictable trajectories which may encompass large areas of the VF (3) signals that move relatively slowly (50 mmsec) (4) signals that recur with a period of 2 to 4 seconds reflecting entrainment by the cortical slow wave (5) signals that do not terminate automatically after a predictable number of cycles

The spatial patterns of phosphene mists and thalamic delta waves are similar The spatiotemporal characteristics of amorphous phosphenes match the pattern of wave propagation associated with periodic spontashy

neous synchronized bursts in large neuron networks the amorphous phosphenes enter the visual field at unpredictable locations expand and diverge asymmetrically with a slow steady rate of flow follow trajectories that are unpredictable and exhibit a refractory interval The amorphous mists do appear to have a periodicity although the author is unable to sustain the vision while also counting the seconds therefore he is unable to determine if it compares to the period of the cortical slow wave (25 to 4 seconds) but his impression is that it feels roughly the same as as with receding annuli which recur at 5 seconds Also the refractory interval feels as if it decreases as the induction session is extended These similarities suggest that the amorphous phosphenes are generated by stage 2 NREMS delta wave activity which is an activity governed by the reverberation of the cortical slow wave in thalamoshycorticothalamic circuits The cortical slow wave is referred to the LGN where it modulates the firing of visual relay cells in the laminae and since relay cells do not have local dendritic connections the expansion of a wave of depolarshyizations moving from one relay cell to the next across in the laminar surface will mirror at least in part the expansion of the cortical wave that is spreading contemporaneously through locally-connected cortical cells

PART III RETENTION OF CONSCIOUSNESS

In a normal transition to NREMS the volley of synchronous spindle bursts that marks the onset of stage 2 NREMS overwhelms the normal firing pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 137

of thalamocortical cells preventing their relay of afferent sensory signals and inducing a loss of consciousness21 But the loss of consciousness cannot be timed precisely using cortical EEG the thalamus is too remote for the onset of spindling to be reliably detected by scalp electrodes39 In experiments with cats where electrodes could be implanted in the thalamus researchers found that spindling often reached peak levels of activity in the thalamus-a level of activity consonant with stage 2 NREMS-at a time when the cortical EEG was still showing intermittent desynchronizations a pattern characteristic of the drowsy stage 1 transition not a fully-established stage 2 NREMS episode4o

In other words there is a short period of time in which the synchronous rhythms of stage 2 NREMS are installed in the thalamus but not in the cortex where cortical neurons continue to depolarize in response to afferent sensory signals

T his finding suggests a possible explanation for the authors ability to retain consciousness while spindle bursts are sweeping through the LGN if he is able to extend the duration of this time lag between

the onset of spindling in the thalamus and spindling in the cortex if he is able to stimulate the visual cortices in such a way that they continue to depolarize then he may be able to keep on processing visual signals-to remain visually aware-even after the non-visual thalamus and non-visual cortex become entrained by synchronous sleep rhythms The authors induction technique includes several behaviors which are known to enhance the responsiveness of visual neurons-eye movements attentive fixation and an attitude of expectancy

Effects of eye movements and attention on the LGN Sustained convergence causes periorbital proprioceptors to send excitatory feedback directly to the LGN41 Also convergence further enhances the excitability of geniculate cells by stimulating the superior collicus (SC) which sends its own excitatory signals to the LGN42-43 These signals from the SC are known to selectively enhance the excitability of visual relay cells that represent the periphery of vision44 We know in the authors case that the SC is being stimulated because he is able to keep on fixating an ability which would normally be lost during the transishytion to NREMS45 The ability to fixate can be retained however if the SC is stimulated (even if stimulated during NREMS)46

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 138

Effects of eye movement attention and expectancy on the primary visual cortex The PET study of mental imagery by Kosslyn et al 3 showed that even a baseline resting state of relaxed immobile expectancy can generate signifishycant increases in neuronal activity in the primary visual cortices Further increases can be induced by sustained eye movements

A sustained convergence will release a stream of ponto-geniculo-occipital (PGO) waves These PGO waves called eye movement potentials or EMPs last only as long as the eye movement1747 whereas the PGO waves associated with rapid-eye-movement sleep (REMS) fire continually for the duration of the REMS episode Both REMS-related PGO waves and EMPs have the same desynchronizing effect on the visual pathways they move through the LGN depolarizing the thalamocortical cells which relay the signals to cortical neurons The responsivity of neurons in the primary visual cortices is enhanced by the stimulation of PGO waves 1747-49 If the passage of EMPs causes the genicushylate relay cells and their cortical targets to depolarize regularly then a volley of 4 spindle bursts moving through the same pathways will register as just another series of depolarizations in effect the spindle bursts are processed by the visual system as if they were sensory signals sent from the retina rather than an event stimulated by endogenous mechanisms

T he impact of eye movements and ftxation on the parietal visual cortex Convergence and attentive fixation will also enhance the responsiveness of light-sensitive parietal visual neurons (PVNs) in area PG of the

posterior parietal cortex 50 In experiments where monkeys are trained to fix their attention on a screen-and to keep on fixating even if no targets appearshythe excitability of these light-sensitive PVNs increases by as much as 350 51

52-53Responsiveness is also facilitated by the angle of gaze Also area PG is the first region in the visual pathways containing individual neurons with the capacity to respond to large bilateral stimuli moving in opposite directions along the central meridians of vision (opponent vector motion) 853-55 Facilitation of PVNs in area PG has the effect of sensitizing the subject to bilateral opponent vector motion and this is especially true if the movement appears in the periphery of the VE 8

Intracortical ampliftcation and feedback to the LGN When PGO waves and signals from the SC arrive in the primary visual cortex they may be relatively weak however weak signals can be amplified by reverberating in large networks

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 139

of cortical cells linked by local projection 56 There are nine times as many excitatory links among cortical cells as there are projections from the visual cortex to the LGN an imbalance which suggests leads Suarez Koch and Douglas to propose that geniculate input provides only a minor fraction of the excitatory input the majority originating in neighboring and recurrently connected cortical cells57 If the excitabiliry of cortical neurons is slightly higher than normal then this process of amplification may continue even after the LGN signals that initiated the reverberation are no longer being transmitted by the LGN ( a hysteretic mode of operation) 57

Feedback from hyperexcited cortical neurons will stream back to the LGN via corticogeniculate projections which outnumber geniculocortical projections ten-to-one One effect of this feedback is that the LGN is

able to absorb large amounts of information flowing back from the cortex 58

As signals reverberate back and forth in thalamocorticothalamic circuits a matching process takes place those geniculate relay cells that fire in patterns consistent with the firing patterns of active cortical cells will have their responshysivity enhanced while those geniculate cells that fire in patterns not consistent with cortical cells will be suppressed 59

Preservation of consciousness by selective facilitation of the visual pathways By combining all of the facilitatory effects produced by the authors eye movements and attentive fixation-(l) stimulation of the LGN by feedback from periorbital proprioception both directly and indirectly via the SC (2) the release of PGO waves (EMPs) that facilitate neurons in the LGN and primary visual cortex as they pass (3) the facilitation of the primary visual cortex by a state of relaxed immobile expectancy (4) attentive fixation and angle of gaze that facilitate PVNs in area PG (5) intracortical amplification of signals received from the LGN and (6) corticogeniculate feedback that stimulates the LGN-we delineate a circuit of enhanced excitability that extends from the LGN through the post-geniculate visual heirarchy to area PG where signals are integrated into representations of objects

The hyperexcitability of neurons all along the post-geniculate visual pathways creates conditions in the visual cortices which are similar to those present during EEG-desynchronized states of waking and REMS Therefore neurons in the visual pathways are too excitable to be entrained by synchronous bursting

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 140

patterns when spindle waves move through them instead the spindle bursts stimulate visual neurons to depolarize and then recover as happens in response to afferent sensory signals during waking states It is important to note that for this to occur none of the constituent neuron assemblies is required to perform an abnormal operation the abnormality is a function of the authors intent to activate contemporaneously neuron assemblies that would not normally be co-activated

PART IV HYPNOTIC ANALGESIA

Manipulation of spatial attention as a method for alleviating pain sensations In a theoretical article on the neurophysiology of hypnosis Crawford and Gruzelier60 propose that variations in hypnotizability are function of variability in the efficiency of the frontolimbic (anterior) attentional system in humans high-hypnotizables are better able to sustain focused attention on a task and to ignore extraneous stimuli than are low-hypnotizables

I na related empirical study that compares the use of attention by subjects with high versus low hypnotizability Crawford Brown and Moon61 report that highly hypnotizable persons continue to show physiological reactivity

while cognitively not perceiving the painful stimuli Through disattentional processes they can dissociate themselves from the awareness of pain The authors phosphene induction behaviors-and the cutaneous analgesia he experishyences-appear to involve the same kind of behaviors that is a mobilization of frontolimbic attention used to withdraw attention from external stimuli and to concentrate it on internally-generated phosphene images This suggests the hypothesis that the mechanisms that generate phosphenes might also produce hypnotic analgesia There are several ways that visual signals and pain signals might interact to produce this analgesia

Competition between pain and vision signals for limbic registration The fully-developed sensation of pain requires integration of rwo kinds of informashytion Signals that encode the location and intensity of a noxious stimulus (nociceptive signals) are relayed via the thalamus to the somatosensory cortices which registers only the sensory-discriminative aspects of pain perception62 before reaching consciousness the nociceptive signals must be sent to the limbic

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 141

system where they are linked with signals from long-term memory that encode the affective significance the stimulus has acquired for that individual Studies of brain metabolism show this linking of somatosensory information with limbic associations takes place in the anterior cingulate (CG) and anterior insula62-64

PET studies also show that the anterior CG is activated when subjects shift their spatial attention in response to expectations as to where

66stimuli will next appear65- This is precisely what takes place during the state of immobile expectancy that induces phosphenes Since visual signals and nociceptive signals both require limbic enhancement which is only possible if they get access to the anterior CG there might be conditions in which the two types of afferent sensory signals have to compete for that access In a theoretical article on the mechanisms of attention Posner and Rothbart67

propose that visual signals can interfere with nociceptive signals by blocking access to the anterior CG As behavioral evidence they cite studies showing that when young infants make distress calls they can be distracted by the presentation of a new visual stimulus We have shown the evidence of such control at about three months Orienting to visual events can be employed to quiet or calm negative vocalizations However the distress appears to be maintained and reappears when the infants attention to the stimulus is reduced Caregivers also report the use or visual orienting to block overt manifestations of distress at about this age 67

The effects of disattention on the somatosensory cortices If there is a competition between visual signals and nociceptive signals for access to the anterior CG it is likely that the competition will be affected by the relative volume of signals received A recent study suggests that focusing attention on internally-generated visual stimuli may reduce the number of nociceptive signals relayed by the somatosensory cortices Drevets Burton Videen Snyder Simpson and Raichle68 have shown that the mere anticipation of a touch at a specific cutaneous site increases the flow of blood to those cortical somatosenshysory neurons that are linked with that site where touch is expected and decreases the flow of blood to neurons linked with sites where touch is not expected In this experiment the researchers designated touch as the behaviorally significant sensory stimulus but their findings suggest that the outcome could be reversed if the instructions were reversed if subjects were

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page J42

instructed to direct attention away from a cutaneous site where a noxious stimulus was being applied if they were instructed to relax close their eyes and concentrate on the play of phosphenes in the visual field as the behaviorally significant sensory stimulus then it would be reasonable to expect that the flow of blood would decrease to the somatosensory neurons linked with the cutaneous stimulus and that the flow of blood would increase to the visual cortices The decrease in blood flow to somatosensory neurons implies less neuronal activity which implies that fewer signals are being sent forward to the anterior CG than would have been sent if instead the subject were treating the touch as the behaviorally significant sensory stimulus If fewer pain signals arrive at the anterior it is reasonable to infer that the conscious experience of pain will be muted by the diversion of attention to internal visual stimuli

Differential impact of sleep rhythms in the visual and nonvisual thalamus There is another mechanism that might also contribute to the analgesic effect of inducing sleep rhythms PET studies show that

the thalamus is involved in the relay of nociceptive signals to the cortex63 although some confusion remains about which kinds of signals are relayed by which subregions in the thalamus62 One thalamic site clearly identified by anatomical studies as a relay for nociceptive signals is the ventroposterior lateral nucleus (VPL)69 If synchronous sleep rhythms are active in the thalamus we can reasonably expect that the VPL will itself be entrained by synchronous oscillations and that it will relay the sleep rhythms to somatosensory cortices Relay neurons in the VPL are not stimulated by feedback from eye movements and fixation as are relay neurons in the LGN which suggests that sleep rhythms may impede the relay of nociceptive signals via the VPL but not the relay of visual signals via the LGN

Brain waves associated with anesthesia and NREMS The hypothesis presented here-that consciousness can be preserved despite the presence of NREMS activity-is consistent with a recent report that the kinds of fast brain waves which are normally associated with conscious states are also present during NREMS and anesthesia two states which were thought to involve minimal brain activityJo Another recent study found that there is a close resemblance between the slow brain waves that appear during NREMS and those that appear during certain types of anesthesia71

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 143

bull bull bull

CONCLUSION

In this paper we have presented evidence supporting the hypothesis that phosphene images can be generated as an epiphenomena of thalamic spindle bursts and delta wave activity normally associated with NREMS The prereqshyuisites for inducing these sleep rhythm phosphenes are relaxed immobile expectancy sustained convergence and attentive fixation of an undifferentiated visual field Our hypothesis provides a necessary and sufficient explanation for the authors induction of phosphenes and perhaps also for the generation of phosphenes reported to appear spontaneously during the drowsy transition to sleep (hypnagogic states) during sensory deprivation or during certain kinds of prayer or meditation all of which involve a similar state of relaxed immobile expectancyJ2

CORRESPONDENCE Philip T Nicholson bull 52 Norfolk Road bull Chestnut Hill MA 02167

REFERENCES amp NOTES

1 M 1 Posner Modulation by Instruction Nature 373 (1995) pp 198-199 2 J Reissenweber E David amp M pfotenhauer Investigations of Psychological Aspects of

the Perception of Magnetophosphenes and Electrophosphenes Biomedizinische Tecknik 373 (1992) pp 42-45

3 S M Kosslyn W L Thompson 1 J Kim amp N M Alpert Topographical Representations of Mental Images in Primary Visual Cortex Nature 378 (I995) pp 496-498

4 P E Roland amp B Gulyas Visual Memory Visual Imagery and Visual Recognition of Large Field Patterns by the Human Brain Functional Anatomy by Positron Emission Tomography Cerebral Cortex 51 (1995) pp 79-93

5 H Benson The Relaxation Response (Morrow New York NY 1975) 6 ] H Schultz amp W Luthe Autogenic Training a Physiological Approach to Psychotherapy

(Grune amp Stratton New York NY 1969) 7 E Jacobson Progressive Relaxation (University of Chicago Press Chicago IL 1938) 8 M A Steinmetz BC Motter C] DuffY amp V B Mountcastle Functional Properties

of Parietal Visual Neurons Radial Organization of Directionalities Within the Visual Field Journal ofNeuroscience 71 (1987) pp 177-191

9 R R Edelman Magnetic Resonance Imaging of the Nervous System Discussions in Neuroscience 71 Elsevier Science Amsterdam (I990) also J H Newhouse amp ] I Wiener Understanding MRI 1st Ed (Little Brown Boston MA 1991)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 144

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

Figure 4 facing page Schematic drawing of contemporaneous events in selected regions of the visual processing hierarchy (A) The left and right RTNs fire spindle bursts simultaneously (B) The bursts pass through the right and left geniculate laminae as standing waves of depolarization entering from the ventral edges and moving ventrodorsally in parallel In order for the phosphene annulus to appear to be flowing at a constant rate the spindle wave flowing through the LCN must expand in width as it ascends ventrodorsally so that by the time the fill-in disk appears-when the center 30deg of the VF is covered by the phosphene annulus-the spindle wave must have expanded enough to activate relay cells in the most dorsal 50 of lamina 6 (C) Signals representing two complementary hemi-annuli are kept separate in the primary visual cortices (area VI) (D) Signals representing the two hemi-annuli are integrated into signals of a single annulus when they reach area PC in the posterior parietal cortex where the receptive fields of single parietal visual neurons have the capacity to register bilateral signals that exhibit opponent vector movement (that is signals converging from opposite directions along the central axes-as if an object were moving away from the viewer)46 Neurons in area PC also integrate wavelength (color) signals from the extrastriate visual pathway with signals about brightness motion and depth from the parietal visual pathway to compose a representation of an object in space-in this case of an annulus that appears to recede 32

the authors experience during MRI when he observed a continuous succession of receding annuli every 2 seconds in this view the energy of the electroshymagnetic bombardment when released during precessional relaxation flows through the geniculate laminae in the same way that the RTN spindle bursts do that is as a standing wave and thus the visual epiphenomenon is the same in both cases if the subject keeps the eyes focused straight ahead and the attention fixated In a study of phosphenes evoked by electricity in conjunction with hallucinogenic drugs Knoll Kugler Hofer and Lawder found that each subject sees specific kinds of phosphene at different frequencies and that these frequency-specific images are stable enough to be reproduced after six months31

They conclude that the tunability of the electrical stimulation frequenshycies within the EEG range to various definable phosphenes requires the existence of a resonance system One mechanism contributing to that resonance system may be the functional anatomy of the LGN

The colors of receding annuli as functions of geniculate laminar anatomy The colors of receding annuli phosphenes are consistent with the patterns of discharge spindle waves can be expected to stimulate as they move through

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 131

geniculate laminae As shown in Figure 5 the six laminae differ (1) in the types of wavelength signals relayed (2) in physical size and (3) in the area of the VF represented 24-25 Only 4 out of 6 laminae Cparvocellular layers 3shy6) contain TC cells that relay wavelength signals the other 2 laminae (magnocellular layers 1 and 2) do not encode wavelength Among parvocelshylular laminae only lamina 6 the longest and most dorsal layer contains TC cells that can represent the far periphery of the VF (from 800 to 50deg of isoeccenshytdeity) therefore when the spindle wave enters the peripheral VF only those wavelengths relayed by lamina 6 will participate in composing a cortical lightness record (See Zeki)32

I n lamina 6 ganglion cell axons arriving from the retina carry two kinds of wavelength signals (1) center-ON signals from medium-wavelength cones (M-cone center-ON) and long-wavelength cones (L-cone centershy

ON)33-35 Using the cone spectral sensitivity curves (adapted from Marks et al 36) we average the wavelengths that elicit maximal responses for M-cones (535 nanometers) and L-cones (520 nm) which yields a mean wavelength value of 550 nm In humans this wavelength generates a sensation of green or yellowshygreen the sensation observed by the author

As the spindle burst moves ventrodorsally it reaches the dorsal areas in the geniculate laminae which contain TC cells representing the central 0deg to 20deg of isoeccentrieity in the VE All 4 parvocellular laminae have TC cells which are potentially capable of representing this central region of vision but the authors observation that the color of the filling-in disk changed from green to blue implies that in the early years of phosphene induction the spindle wave must have remained close to the surface of the LGN stimulating only laminae 5 and 6 which generates a sensation of yellow-green When the fill-in disk was observed to change color from green to blue the spindle wave must have been rechanneled so that it began to penetrate below laminae 5 and 6 and to activate laminae 3 and 4 the only laminae that relay blue-sensitive signals (Sshycone center-ON signals)3 In light of the authors MRI experience it seems likely that a spindle wave requires a minimum of 2 seconds to reach the blueshysensitive cells of laminae 4 therefore during MRI when the receding annuli disappeared after 2 seconds half the normal duration the fill-disk had a green color even though it had long since change to blue in other induction settings with a 4-second trajectory

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 132

A REPRESENTATION OF THE VISUAL FIELD IN EACH LAMINA

orooqUtftc O-u OCIJ1SALfIOLI (I01flAj

0

10

20

30

40 n50 Of

60

70

20 loO 1Mgr_ II~ o UIpoundAS65 mn1MY-o actlvncL ~~~r

Jll-COMcetlImiddot~

II LAYERSU 3 GatQYancetl~ (1) ucon ceom-oyenF (2)l~cen()FF 3) ~ cenloH

II~ cng1loqctWIIIfNla

iICINe -- (t81Otdb1t1d~OH (2)~

80

B CONE SPECTRAL SENSITIVITY CURVES

S-COHS

WAVIlLllNG1llS OF UGHT IH NANOMllTERS (NM)

Figure 5 Phosphene color as a function of ganglion cell distribution in parvocellular laminae (Aj Schematic drawing ofthe proportion ofthe VF represented in each laminae The proportions shown here are based on the work of Connolly and Van Essen24 The

far periphery of vision (50 0 to 80 0 of isoeccentricity) is represented in only two laminae-laminae 1 and 6-and of these two only lamina 6 is a parvocelLular lamina capable ofencoding wavelength signals Therefore only those wavelengths relayed by lamina 6 will participate in forming a cortical lighmess record for the far periphery of the VP (B) Cone spectral sensitivity curves (adapted from Marks et al)36 Using these cone sensitivity curves we can estimate the sensation stimulated by a spindle wave moving through lamina 6 by averaging the wavelengths that elicit maximal responses for M-cones (535 nanomeshyters) and L-cones (520 nm) which yields a mean wavelength value of550 nm In humans this generates a sensation of green or yellow-green the sensation observed by the author when the receding annulus enters at the far periphery of the VP For a calculation of the cortical lightness record when a spindle wave moves through 20deg to 0deg ofthe VF stimulating all 4 parvocelfular laminae see the text and Figure 6

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 133

Once the spindle wave penetrates to laminae 3 and 4 it may activate all 4 parvocellular laminae stimulating TC cells to send contradictory wavelength signals for the same retinotopic location the signals sent from laminae 4 and 3 will encode blue light (S-cone center-ON plus M-cone center-OFF and Lshycone center-OFF) while the signals sent from laminae 5 and 6 encode yellowshygreen light (M-cone center-ON plus L-cone center-ON) This kind of contrashydiction does not occur in normal retina-based perception where light energy striking the retina is structured by the retinas center-surround and colorshyopponent organization to encode only one set of wavelength signals for each spatial locus 32 In Figure 6 we estimate the cortical lightness record that results when contradictory wavelength signals compete to be represented in consciousshyness Our calculations suggest that the outcome will be a mean wavelength which in humans elicits a dark blue or violet sensation

PART II AMORPHOUS PHOSPHENES amp THALAMIC DELTA ACTMTY

M echanisms controlling the transition from spindle bursts to delta activity In the consensus scenario for the generation of NREMS16-20 we noted that the RTN shifts to firing spindle bursts

when polarization of thalamic cell membranes drops to V m = - 60 mV At the same time cortical cells begin oscillating with a synchronous slow rhythm laquo 1 Hz) Both processes further decrease the Vm of TC cell membranes When Vm = - 75 mY TC cells begin to generate their own intrinsic calcium currents which also decreases V m At V m = - 90 mV RTN neurons stop firing spindle bursts At the same time the TC cells begin firing low-threshold calcium spikes in alternation with after-hyperpolarizations (LTS-AHP) Because sensory relay neurons in the LGN are not linked to one another by locally projecting axons the firing of one TC cell does not excite its neighbor However a lack of local connectivity does not mean that TC cells occupying the same laminae release their AHP-LTS calcium spikes in a random distribshyution rather spikes are released simultaneously by groups of cells in synchrony with the advent of the cortical slow wave In effect the distribution of LTSshyAHP spikes firing in the LGN is determined by the spatial propagation of the cortical slow wave Thus the delta wave (1 to 4 Hz) activity detected by cortical EEG during NREMS is a product of the interaction between the AHP-LTS calcium spikes released by TC cells and the cortical slow rhythm

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 134

CORTICAL PROCESSING OF CONTRADICTORY

WAVELENGTH SIGNALS

KEY _ Cells firing

cJ Cononol firing

Assume that as a spind6e wave moves through the LGNlt fires simultaneously aU the TC cells that represent a particular reUnoshytopic locus (x y) in each of the six laminae As a result cortical cells engaged In the higher level processing of visual signals will receive more wavelength signals representing retina locus (x y) than are generated by normal perception laquo and some of these afferent wavelength signals may contradict other signals arriving simultaneously

CORTICAL LIGHTNESS RECORD SlgnalSell

Intemal contradictions not congruent wilt pre

SmiddotON eristing neuron neta

s bullbull M-ON LmiddotON

3 bullbull M-OFF + L-OFF

a-ON 12

ROD-ON

No Internal eonlradlemiddot

--------1I =~8b~~~~~~~t signals

3+4

~ --OFF Excludes 6 Of 7 $J9n18

1+2 B-ON I

IWmiddotHmiddotI Signal Sell

1111111 No Intern1 conlrfldlcshy lion

Exelvdta 4 out of 7 efshy

bullbullbull bullbullbull ferant signals

No Intern1 contradic_ tionnee S-ON BshyOH and ROO-ON can all be coacllve at low lImlnance levels nef Ihe rod-eone break

ExchJde$ only 2 Ollt of 7 afferent signals

Figure 6 Selection of competing wavelength signals based on neuronal group selection This thought experiment is based on Edelman sconcept ofneuronal group selection 73 We assume that all possible combinations ofsignals will form sets and that all signal-sets will compete to make the most efficient match with pre-existing neuromd networks that have been forged over years ofnorma reti1U1-based perception We also assume that pre-existing neural networks are most likely to expedite those sets that satisfY 2 criteriI (J) the signals in a set do not contradict each other and (2) fower signals are excluded than in the other sets that satisfY the first criterion In our analysis Set 4 wins the competition because it does not contain internal contradictions and excludes fower signals (2 out of 7) than Set 3 excludes (4 out of7) It is not an internal contradiction that Set 4 contains both rods and cone Signtlls in normal retina-based perception when luminance levels approach the rod-cone break S-cone center-ON receptors send signas as do rod receptors and there is even evidence that rod activity may actually drive S-cone activity even after luminance levels foIl below the rod-cone break74 To calculate the cortical lightness record for Set 4 we average the wavelength that elicits maximal responses foom rods (511 nm) and for Sshycones (430 nm) which yields a mean wavelength of 470 nm which in humans results in a dark-blue or violet sensation

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 135

The cortical slow rhythm is an example of a generic pattern of neuronal excitashytion that occurs in large networks of neurons linked by local projections A recent experiment by Maeda Robinson and Kwana38 shows that networks of locally-connected neurons spontaneously generate periodic synchronized bursts of calcium transients that propagate across the network in an expanding spatial wave a pattern that represents a stable mode of firing towards which these neuronal networks relax following perturbations for example by electronic stimulation or by drugs Understanding the characteristics of these waves is an important prerequisite to understanding the mechanisms that produce the amorphous phosphene images as a visual epiphenomenon

To study the spontaneous periodic synchronized bursts the researchers prepared cultures of dissociated cortical neurons and allowed them to mature for several days in vitro (DIV) After 3 to 4 DIV when concenshy

trations of extracellular magnesium were low electrodes began to detect spontaneous synchronized bursts of low frequency calcium transients (between 01 and 1 Hz) that originated in different locations on the sheet every 10 to 20 seconds and spread across the sheet of cells at a relatively slow speed averaging 50 mmsecond The researchers could not predict where a wave would originate or where it would expand rather the initiation and expansion of waves was generated by spatial and temporal summation of a continuous random background of synaptic inputs including miniature spontaneous synaptic events but the pattern was not random since waves propagated sequentially from electrode to electrode as each local group of neurons charges up its neighboring nontefractory areas rather than in a random sequence of regions38

The excitability of the cells in the sheet determines the probability first that there will be a synchronous burst and second that it will spread in a particshyular direction Cells become more excitable as the cultures mature which means the refractory intervals between successive bursts were much shorter in mature cultures (gt 30 DIV) than in early cultures laquo 7 DIV) Some cells became so insensitive to inhibition that they continued to fire bursts even when extracellular concentrations of magnesium were relatively high Finally there were refractory periods of 5 to 10 seconds during which no bursts occurred even when an electrical stimulus was applied This refractory interval for cultured networks is slightly longer than the refractory interval observed of the cortical slow wave in vivo which 25 to 4 seconds 18- 19

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 136

Based on the observations about cortical slow waves we can predict that phosphenes generated as epiphenomena of delta wave activity will present the following signal characteristics (1) signals that appear at unpredictable locations in the VF (2) signals that expand and diverge asymmetrically following unpredictable trajectories which may encompass large areas of the VF (3) signals that move relatively slowly (50 mmsec) (4) signals that recur with a period of 2 to 4 seconds reflecting entrainment by the cortical slow wave (5) signals that do not terminate automatically after a predictable number of cycles

The spatial patterns of phosphene mists and thalamic delta waves are similar The spatiotemporal characteristics of amorphous phosphenes match the pattern of wave propagation associated with periodic spontashy

neous synchronized bursts in large neuron networks the amorphous phosphenes enter the visual field at unpredictable locations expand and diverge asymmetrically with a slow steady rate of flow follow trajectories that are unpredictable and exhibit a refractory interval The amorphous mists do appear to have a periodicity although the author is unable to sustain the vision while also counting the seconds therefore he is unable to determine if it compares to the period of the cortical slow wave (25 to 4 seconds) but his impression is that it feels roughly the same as as with receding annuli which recur at 5 seconds Also the refractory interval feels as if it decreases as the induction session is extended These similarities suggest that the amorphous phosphenes are generated by stage 2 NREMS delta wave activity which is an activity governed by the reverberation of the cortical slow wave in thalamoshycorticothalamic circuits The cortical slow wave is referred to the LGN where it modulates the firing of visual relay cells in the laminae and since relay cells do not have local dendritic connections the expansion of a wave of depolarshyizations moving from one relay cell to the next across in the laminar surface will mirror at least in part the expansion of the cortical wave that is spreading contemporaneously through locally-connected cortical cells

PART III RETENTION OF CONSCIOUSNESS

In a normal transition to NREMS the volley of synchronous spindle bursts that marks the onset of stage 2 NREMS overwhelms the normal firing pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 137

of thalamocortical cells preventing their relay of afferent sensory signals and inducing a loss of consciousness21 But the loss of consciousness cannot be timed precisely using cortical EEG the thalamus is too remote for the onset of spindling to be reliably detected by scalp electrodes39 In experiments with cats where electrodes could be implanted in the thalamus researchers found that spindling often reached peak levels of activity in the thalamus-a level of activity consonant with stage 2 NREMS-at a time when the cortical EEG was still showing intermittent desynchronizations a pattern characteristic of the drowsy stage 1 transition not a fully-established stage 2 NREMS episode4o

In other words there is a short period of time in which the synchronous rhythms of stage 2 NREMS are installed in the thalamus but not in the cortex where cortical neurons continue to depolarize in response to afferent sensory signals

T his finding suggests a possible explanation for the authors ability to retain consciousness while spindle bursts are sweeping through the LGN if he is able to extend the duration of this time lag between

the onset of spindling in the thalamus and spindling in the cortex if he is able to stimulate the visual cortices in such a way that they continue to depolarize then he may be able to keep on processing visual signals-to remain visually aware-even after the non-visual thalamus and non-visual cortex become entrained by synchronous sleep rhythms The authors induction technique includes several behaviors which are known to enhance the responsiveness of visual neurons-eye movements attentive fixation and an attitude of expectancy

Effects of eye movements and attention on the LGN Sustained convergence causes periorbital proprioceptors to send excitatory feedback directly to the LGN41 Also convergence further enhances the excitability of geniculate cells by stimulating the superior collicus (SC) which sends its own excitatory signals to the LGN42-43 These signals from the SC are known to selectively enhance the excitability of visual relay cells that represent the periphery of vision44 We know in the authors case that the SC is being stimulated because he is able to keep on fixating an ability which would normally be lost during the transishytion to NREMS45 The ability to fixate can be retained however if the SC is stimulated (even if stimulated during NREMS)46

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 138

Effects of eye movement attention and expectancy on the primary visual cortex The PET study of mental imagery by Kosslyn et al 3 showed that even a baseline resting state of relaxed immobile expectancy can generate signifishycant increases in neuronal activity in the primary visual cortices Further increases can be induced by sustained eye movements

A sustained convergence will release a stream of ponto-geniculo-occipital (PGO) waves These PGO waves called eye movement potentials or EMPs last only as long as the eye movement1747 whereas the PGO waves associated with rapid-eye-movement sleep (REMS) fire continually for the duration of the REMS episode Both REMS-related PGO waves and EMPs have the same desynchronizing effect on the visual pathways they move through the LGN depolarizing the thalamocortical cells which relay the signals to cortical neurons The responsivity of neurons in the primary visual cortices is enhanced by the stimulation of PGO waves 1747-49 If the passage of EMPs causes the genicushylate relay cells and their cortical targets to depolarize regularly then a volley of 4 spindle bursts moving through the same pathways will register as just another series of depolarizations in effect the spindle bursts are processed by the visual system as if they were sensory signals sent from the retina rather than an event stimulated by endogenous mechanisms

T he impact of eye movements and ftxation on the parietal visual cortex Convergence and attentive fixation will also enhance the responsiveness of light-sensitive parietal visual neurons (PVNs) in area PG of the

posterior parietal cortex 50 In experiments where monkeys are trained to fix their attention on a screen-and to keep on fixating even if no targets appearshythe excitability of these light-sensitive PVNs increases by as much as 350 51

52-53Responsiveness is also facilitated by the angle of gaze Also area PG is the first region in the visual pathways containing individual neurons with the capacity to respond to large bilateral stimuli moving in opposite directions along the central meridians of vision (opponent vector motion) 853-55 Facilitation of PVNs in area PG has the effect of sensitizing the subject to bilateral opponent vector motion and this is especially true if the movement appears in the periphery of the VE 8

Intracortical ampliftcation and feedback to the LGN When PGO waves and signals from the SC arrive in the primary visual cortex they may be relatively weak however weak signals can be amplified by reverberating in large networks

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 139

of cortical cells linked by local projection 56 There are nine times as many excitatory links among cortical cells as there are projections from the visual cortex to the LGN an imbalance which suggests leads Suarez Koch and Douglas to propose that geniculate input provides only a minor fraction of the excitatory input the majority originating in neighboring and recurrently connected cortical cells57 If the excitabiliry of cortical neurons is slightly higher than normal then this process of amplification may continue even after the LGN signals that initiated the reverberation are no longer being transmitted by the LGN ( a hysteretic mode of operation) 57

Feedback from hyperexcited cortical neurons will stream back to the LGN via corticogeniculate projections which outnumber geniculocortical projections ten-to-one One effect of this feedback is that the LGN is

able to absorb large amounts of information flowing back from the cortex 58

As signals reverberate back and forth in thalamocorticothalamic circuits a matching process takes place those geniculate relay cells that fire in patterns consistent with the firing patterns of active cortical cells will have their responshysivity enhanced while those geniculate cells that fire in patterns not consistent with cortical cells will be suppressed 59

Preservation of consciousness by selective facilitation of the visual pathways By combining all of the facilitatory effects produced by the authors eye movements and attentive fixation-(l) stimulation of the LGN by feedback from periorbital proprioception both directly and indirectly via the SC (2) the release of PGO waves (EMPs) that facilitate neurons in the LGN and primary visual cortex as they pass (3) the facilitation of the primary visual cortex by a state of relaxed immobile expectancy (4) attentive fixation and angle of gaze that facilitate PVNs in area PG (5) intracortical amplification of signals received from the LGN and (6) corticogeniculate feedback that stimulates the LGN-we delineate a circuit of enhanced excitability that extends from the LGN through the post-geniculate visual heirarchy to area PG where signals are integrated into representations of objects

The hyperexcitability of neurons all along the post-geniculate visual pathways creates conditions in the visual cortices which are similar to those present during EEG-desynchronized states of waking and REMS Therefore neurons in the visual pathways are too excitable to be entrained by synchronous bursting

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 140

patterns when spindle waves move through them instead the spindle bursts stimulate visual neurons to depolarize and then recover as happens in response to afferent sensory signals during waking states It is important to note that for this to occur none of the constituent neuron assemblies is required to perform an abnormal operation the abnormality is a function of the authors intent to activate contemporaneously neuron assemblies that would not normally be co-activated

PART IV HYPNOTIC ANALGESIA

Manipulation of spatial attention as a method for alleviating pain sensations In a theoretical article on the neurophysiology of hypnosis Crawford and Gruzelier60 propose that variations in hypnotizability are function of variability in the efficiency of the frontolimbic (anterior) attentional system in humans high-hypnotizables are better able to sustain focused attention on a task and to ignore extraneous stimuli than are low-hypnotizables

I na related empirical study that compares the use of attention by subjects with high versus low hypnotizability Crawford Brown and Moon61 report that highly hypnotizable persons continue to show physiological reactivity

while cognitively not perceiving the painful stimuli Through disattentional processes they can dissociate themselves from the awareness of pain The authors phosphene induction behaviors-and the cutaneous analgesia he experishyences-appear to involve the same kind of behaviors that is a mobilization of frontolimbic attention used to withdraw attention from external stimuli and to concentrate it on internally-generated phosphene images This suggests the hypothesis that the mechanisms that generate phosphenes might also produce hypnotic analgesia There are several ways that visual signals and pain signals might interact to produce this analgesia

Competition between pain and vision signals for limbic registration The fully-developed sensation of pain requires integration of rwo kinds of informashytion Signals that encode the location and intensity of a noxious stimulus (nociceptive signals) are relayed via the thalamus to the somatosensory cortices which registers only the sensory-discriminative aspects of pain perception62 before reaching consciousness the nociceptive signals must be sent to the limbic

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 141

system where they are linked with signals from long-term memory that encode the affective significance the stimulus has acquired for that individual Studies of brain metabolism show this linking of somatosensory information with limbic associations takes place in the anterior cingulate (CG) and anterior insula62-64

PET studies also show that the anterior CG is activated when subjects shift their spatial attention in response to expectations as to where

66stimuli will next appear65- This is precisely what takes place during the state of immobile expectancy that induces phosphenes Since visual signals and nociceptive signals both require limbic enhancement which is only possible if they get access to the anterior CG there might be conditions in which the two types of afferent sensory signals have to compete for that access In a theoretical article on the mechanisms of attention Posner and Rothbart67

propose that visual signals can interfere with nociceptive signals by blocking access to the anterior CG As behavioral evidence they cite studies showing that when young infants make distress calls they can be distracted by the presentation of a new visual stimulus We have shown the evidence of such control at about three months Orienting to visual events can be employed to quiet or calm negative vocalizations However the distress appears to be maintained and reappears when the infants attention to the stimulus is reduced Caregivers also report the use or visual orienting to block overt manifestations of distress at about this age 67

The effects of disattention on the somatosensory cortices If there is a competition between visual signals and nociceptive signals for access to the anterior CG it is likely that the competition will be affected by the relative volume of signals received A recent study suggests that focusing attention on internally-generated visual stimuli may reduce the number of nociceptive signals relayed by the somatosensory cortices Drevets Burton Videen Snyder Simpson and Raichle68 have shown that the mere anticipation of a touch at a specific cutaneous site increases the flow of blood to those cortical somatosenshysory neurons that are linked with that site where touch is expected and decreases the flow of blood to neurons linked with sites where touch is not expected In this experiment the researchers designated touch as the behaviorally significant sensory stimulus but their findings suggest that the outcome could be reversed if the instructions were reversed if subjects were

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page J42

instructed to direct attention away from a cutaneous site where a noxious stimulus was being applied if they were instructed to relax close their eyes and concentrate on the play of phosphenes in the visual field as the behaviorally significant sensory stimulus then it would be reasonable to expect that the flow of blood would decrease to the somatosensory neurons linked with the cutaneous stimulus and that the flow of blood would increase to the visual cortices The decrease in blood flow to somatosensory neurons implies less neuronal activity which implies that fewer signals are being sent forward to the anterior CG than would have been sent if instead the subject were treating the touch as the behaviorally significant sensory stimulus If fewer pain signals arrive at the anterior it is reasonable to infer that the conscious experience of pain will be muted by the diversion of attention to internal visual stimuli

Differential impact of sleep rhythms in the visual and nonvisual thalamus There is another mechanism that might also contribute to the analgesic effect of inducing sleep rhythms PET studies show that

the thalamus is involved in the relay of nociceptive signals to the cortex63 although some confusion remains about which kinds of signals are relayed by which subregions in the thalamus62 One thalamic site clearly identified by anatomical studies as a relay for nociceptive signals is the ventroposterior lateral nucleus (VPL)69 If synchronous sleep rhythms are active in the thalamus we can reasonably expect that the VPL will itself be entrained by synchronous oscillations and that it will relay the sleep rhythms to somatosensory cortices Relay neurons in the VPL are not stimulated by feedback from eye movements and fixation as are relay neurons in the LGN which suggests that sleep rhythms may impede the relay of nociceptive signals via the VPL but not the relay of visual signals via the LGN

Brain waves associated with anesthesia and NREMS The hypothesis presented here-that consciousness can be preserved despite the presence of NREMS activity-is consistent with a recent report that the kinds of fast brain waves which are normally associated with conscious states are also present during NREMS and anesthesia two states which were thought to involve minimal brain activityJo Another recent study found that there is a close resemblance between the slow brain waves that appear during NREMS and those that appear during certain types of anesthesia71

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 143

bull bull bull

CONCLUSION

In this paper we have presented evidence supporting the hypothesis that phosphene images can be generated as an epiphenomena of thalamic spindle bursts and delta wave activity normally associated with NREMS The prereqshyuisites for inducing these sleep rhythm phosphenes are relaxed immobile expectancy sustained convergence and attentive fixation of an undifferentiated visual field Our hypothesis provides a necessary and sufficient explanation for the authors induction of phosphenes and perhaps also for the generation of phosphenes reported to appear spontaneously during the drowsy transition to sleep (hypnagogic states) during sensory deprivation or during certain kinds of prayer or meditation all of which involve a similar state of relaxed immobile expectancyJ2

CORRESPONDENCE Philip T Nicholson bull 52 Norfolk Road bull Chestnut Hill MA 02167

REFERENCES amp NOTES

1 M 1 Posner Modulation by Instruction Nature 373 (1995) pp 198-199 2 J Reissenweber E David amp M pfotenhauer Investigations of Psychological Aspects of

the Perception of Magnetophosphenes and Electrophosphenes Biomedizinische Tecknik 373 (1992) pp 42-45

3 S M Kosslyn W L Thompson 1 J Kim amp N M Alpert Topographical Representations of Mental Images in Primary Visual Cortex Nature 378 (I995) pp 496-498

4 P E Roland amp B Gulyas Visual Memory Visual Imagery and Visual Recognition of Large Field Patterns by the Human Brain Functional Anatomy by Positron Emission Tomography Cerebral Cortex 51 (1995) pp 79-93

5 H Benson The Relaxation Response (Morrow New York NY 1975) 6 ] H Schultz amp W Luthe Autogenic Training a Physiological Approach to Psychotherapy

(Grune amp Stratton New York NY 1969) 7 E Jacobson Progressive Relaxation (University of Chicago Press Chicago IL 1938) 8 M A Steinmetz BC Motter C] DuffY amp V B Mountcastle Functional Properties

of Parietal Visual Neurons Radial Organization of Directionalities Within the Visual Field Journal ofNeuroscience 71 (1987) pp 177-191

9 R R Edelman Magnetic Resonance Imaging of the Nervous System Discussions in Neuroscience 71 Elsevier Science Amsterdam (I990) also J H Newhouse amp ] I Wiener Understanding MRI 1st Ed (Little Brown Boston MA 1991)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 144

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

geniculate laminae As shown in Figure 5 the six laminae differ (1) in the types of wavelength signals relayed (2) in physical size and (3) in the area of the VF represented 24-25 Only 4 out of 6 laminae Cparvocellular layers 3shy6) contain TC cells that relay wavelength signals the other 2 laminae (magnocellular layers 1 and 2) do not encode wavelength Among parvocelshylular laminae only lamina 6 the longest and most dorsal layer contains TC cells that can represent the far periphery of the VF (from 800 to 50deg of isoeccenshytdeity) therefore when the spindle wave enters the peripheral VF only those wavelengths relayed by lamina 6 will participate in composing a cortical lightness record (See Zeki)32

I n lamina 6 ganglion cell axons arriving from the retina carry two kinds of wavelength signals (1) center-ON signals from medium-wavelength cones (M-cone center-ON) and long-wavelength cones (L-cone centershy

ON)33-35 Using the cone spectral sensitivity curves (adapted from Marks et al 36) we average the wavelengths that elicit maximal responses for M-cones (535 nanometers) and L-cones (520 nm) which yields a mean wavelength value of 550 nm In humans this wavelength generates a sensation of green or yellowshygreen the sensation observed by the author

As the spindle burst moves ventrodorsally it reaches the dorsal areas in the geniculate laminae which contain TC cells representing the central 0deg to 20deg of isoeccentrieity in the VE All 4 parvocellular laminae have TC cells which are potentially capable of representing this central region of vision but the authors observation that the color of the filling-in disk changed from green to blue implies that in the early years of phosphene induction the spindle wave must have remained close to the surface of the LGN stimulating only laminae 5 and 6 which generates a sensation of yellow-green When the fill-in disk was observed to change color from green to blue the spindle wave must have been rechanneled so that it began to penetrate below laminae 5 and 6 and to activate laminae 3 and 4 the only laminae that relay blue-sensitive signals (Sshycone center-ON signals)3 In light of the authors MRI experience it seems likely that a spindle wave requires a minimum of 2 seconds to reach the blueshysensitive cells of laminae 4 therefore during MRI when the receding annuli disappeared after 2 seconds half the normal duration the fill-disk had a green color even though it had long since change to blue in other induction settings with a 4-second trajectory

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 132

A REPRESENTATION OF THE VISUAL FIELD IN EACH LAMINA

orooqUtftc O-u OCIJ1SALfIOLI (I01flAj

0

10

20

30

40 n50 Of

60

70

20 loO 1Mgr_ II~ o UIpoundAS65 mn1MY-o actlvncL ~~~r

Jll-COMcetlImiddot~

II LAYERSU 3 GatQYancetl~ (1) ucon ceom-oyenF (2)l~cen()FF 3) ~ cenloH

II~ cng1loqctWIIIfNla

iICINe -- (t81Otdb1t1d~OH (2)~

80

B CONE SPECTRAL SENSITIVITY CURVES

S-COHS

WAVIlLllNG1llS OF UGHT IH NANOMllTERS (NM)

Figure 5 Phosphene color as a function of ganglion cell distribution in parvocellular laminae (Aj Schematic drawing ofthe proportion ofthe VF represented in each laminae The proportions shown here are based on the work of Connolly and Van Essen24 The

far periphery of vision (50 0 to 80 0 of isoeccentricity) is represented in only two laminae-laminae 1 and 6-and of these two only lamina 6 is a parvocelLular lamina capable ofencoding wavelength signals Therefore only those wavelengths relayed by lamina 6 will participate in forming a cortical lighmess record for the far periphery of the VP (B) Cone spectral sensitivity curves (adapted from Marks et al)36 Using these cone sensitivity curves we can estimate the sensation stimulated by a spindle wave moving through lamina 6 by averaging the wavelengths that elicit maximal responses for M-cones (535 nanomeshyters) and L-cones (520 nm) which yields a mean wavelength value of550 nm In humans this generates a sensation of green or yellow-green the sensation observed by the author when the receding annulus enters at the far periphery of the VP For a calculation of the cortical lightness record when a spindle wave moves through 20deg to 0deg ofthe VF stimulating all 4 parvocelfular laminae see the text and Figure 6

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 133

Once the spindle wave penetrates to laminae 3 and 4 it may activate all 4 parvocellular laminae stimulating TC cells to send contradictory wavelength signals for the same retinotopic location the signals sent from laminae 4 and 3 will encode blue light (S-cone center-ON plus M-cone center-OFF and Lshycone center-OFF) while the signals sent from laminae 5 and 6 encode yellowshygreen light (M-cone center-ON plus L-cone center-ON) This kind of contrashydiction does not occur in normal retina-based perception where light energy striking the retina is structured by the retinas center-surround and colorshyopponent organization to encode only one set of wavelength signals for each spatial locus 32 In Figure 6 we estimate the cortical lightness record that results when contradictory wavelength signals compete to be represented in consciousshyness Our calculations suggest that the outcome will be a mean wavelength which in humans elicits a dark blue or violet sensation

PART II AMORPHOUS PHOSPHENES amp THALAMIC DELTA ACTMTY

M echanisms controlling the transition from spindle bursts to delta activity In the consensus scenario for the generation of NREMS16-20 we noted that the RTN shifts to firing spindle bursts

when polarization of thalamic cell membranes drops to V m = - 60 mV At the same time cortical cells begin oscillating with a synchronous slow rhythm laquo 1 Hz) Both processes further decrease the Vm of TC cell membranes When Vm = - 75 mY TC cells begin to generate their own intrinsic calcium currents which also decreases V m At V m = - 90 mV RTN neurons stop firing spindle bursts At the same time the TC cells begin firing low-threshold calcium spikes in alternation with after-hyperpolarizations (LTS-AHP) Because sensory relay neurons in the LGN are not linked to one another by locally projecting axons the firing of one TC cell does not excite its neighbor However a lack of local connectivity does not mean that TC cells occupying the same laminae release their AHP-LTS calcium spikes in a random distribshyution rather spikes are released simultaneously by groups of cells in synchrony with the advent of the cortical slow wave In effect the distribution of LTSshyAHP spikes firing in the LGN is determined by the spatial propagation of the cortical slow wave Thus the delta wave (1 to 4 Hz) activity detected by cortical EEG during NREMS is a product of the interaction between the AHP-LTS calcium spikes released by TC cells and the cortical slow rhythm

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 134

CORTICAL PROCESSING OF CONTRADICTORY

WAVELENGTH SIGNALS

KEY _ Cells firing

cJ Cononol firing

Assume that as a spind6e wave moves through the LGNlt fires simultaneously aU the TC cells that represent a particular reUnoshytopic locus (x y) in each of the six laminae As a result cortical cells engaged In the higher level processing of visual signals will receive more wavelength signals representing retina locus (x y) than are generated by normal perception laquo and some of these afferent wavelength signals may contradict other signals arriving simultaneously

CORTICAL LIGHTNESS RECORD SlgnalSell

Intemal contradictions not congruent wilt pre

SmiddotON eristing neuron neta

s bullbull M-ON LmiddotON

3 bullbull M-OFF + L-OFF

a-ON 12

ROD-ON

No Internal eonlradlemiddot

--------1I =~8b~~~~~~~t signals

3+4

~ --OFF Excludes 6 Of 7 $J9n18

1+2 B-ON I

IWmiddotHmiddotI Signal Sell

1111111 No Intern1 conlrfldlcshy lion

Exelvdta 4 out of 7 efshy

bullbullbull bullbullbull ferant signals

No Intern1 contradic_ tionnee S-ON BshyOH and ROO-ON can all be coacllve at low lImlnance levels nef Ihe rod-eone break

ExchJde$ only 2 Ollt of 7 afferent signals

Figure 6 Selection of competing wavelength signals based on neuronal group selection This thought experiment is based on Edelman sconcept ofneuronal group selection 73 We assume that all possible combinations ofsignals will form sets and that all signal-sets will compete to make the most efficient match with pre-existing neuromd networks that have been forged over years ofnorma reti1U1-based perception We also assume that pre-existing neural networks are most likely to expedite those sets that satisfY 2 criteriI (J) the signals in a set do not contradict each other and (2) fower signals are excluded than in the other sets that satisfY the first criterion In our analysis Set 4 wins the competition because it does not contain internal contradictions and excludes fower signals (2 out of 7) than Set 3 excludes (4 out of7) It is not an internal contradiction that Set 4 contains both rods and cone Signtlls in normal retina-based perception when luminance levels approach the rod-cone break S-cone center-ON receptors send signas as do rod receptors and there is even evidence that rod activity may actually drive S-cone activity even after luminance levels foIl below the rod-cone break74 To calculate the cortical lightness record for Set 4 we average the wavelength that elicits maximal responses foom rods (511 nm) and for Sshycones (430 nm) which yields a mean wavelength of 470 nm which in humans results in a dark-blue or violet sensation

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 135

The cortical slow rhythm is an example of a generic pattern of neuronal excitashytion that occurs in large networks of neurons linked by local projections A recent experiment by Maeda Robinson and Kwana38 shows that networks of locally-connected neurons spontaneously generate periodic synchronized bursts of calcium transients that propagate across the network in an expanding spatial wave a pattern that represents a stable mode of firing towards which these neuronal networks relax following perturbations for example by electronic stimulation or by drugs Understanding the characteristics of these waves is an important prerequisite to understanding the mechanisms that produce the amorphous phosphene images as a visual epiphenomenon

To study the spontaneous periodic synchronized bursts the researchers prepared cultures of dissociated cortical neurons and allowed them to mature for several days in vitro (DIV) After 3 to 4 DIV when concenshy

trations of extracellular magnesium were low electrodes began to detect spontaneous synchronized bursts of low frequency calcium transients (between 01 and 1 Hz) that originated in different locations on the sheet every 10 to 20 seconds and spread across the sheet of cells at a relatively slow speed averaging 50 mmsecond The researchers could not predict where a wave would originate or where it would expand rather the initiation and expansion of waves was generated by spatial and temporal summation of a continuous random background of synaptic inputs including miniature spontaneous synaptic events but the pattern was not random since waves propagated sequentially from electrode to electrode as each local group of neurons charges up its neighboring nontefractory areas rather than in a random sequence of regions38

The excitability of the cells in the sheet determines the probability first that there will be a synchronous burst and second that it will spread in a particshyular direction Cells become more excitable as the cultures mature which means the refractory intervals between successive bursts were much shorter in mature cultures (gt 30 DIV) than in early cultures laquo 7 DIV) Some cells became so insensitive to inhibition that they continued to fire bursts even when extracellular concentrations of magnesium were relatively high Finally there were refractory periods of 5 to 10 seconds during which no bursts occurred even when an electrical stimulus was applied This refractory interval for cultured networks is slightly longer than the refractory interval observed of the cortical slow wave in vivo which 25 to 4 seconds 18- 19

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 136

Based on the observations about cortical slow waves we can predict that phosphenes generated as epiphenomena of delta wave activity will present the following signal characteristics (1) signals that appear at unpredictable locations in the VF (2) signals that expand and diverge asymmetrically following unpredictable trajectories which may encompass large areas of the VF (3) signals that move relatively slowly (50 mmsec) (4) signals that recur with a period of 2 to 4 seconds reflecting entrainment by the cortical slow wave (5) signals that do not terminate automatically after a predictable number of cycles

The spatial patterns of phosphene mists and thalamic delta waves are similar The spatiotemporal characteristics of amorphous phosphenes match the pattern of wave propagation associated with periodic spontashy

neous synchronized bursts in large neuron networks the amorphous phosphenes enter the visual field at unpredictable locations expand and diverge asymmetrically with a slow steady rate of flow follow trajectories that are unpredictable and exhibit a refractory interval The amorphous mists do appear to have a periodicity although the author is unable to sustain the vision while also counting the seconds therefore he is unable to determine if it compares to the period of the cortical slow wave (25 to 4 seconds) but his impression is that it feels roughly the same as as with receding annuli which recur at 5 seconds Also the refractory interval feels as if it decreases as the induction session is extended These similarities suggest that the amorphous phosphenes are generated by stage 2 NREMS delta wave activity which is an activity governed by the reverberation of the cortical slow wave in thalamoshycorticothalamic circuits The cortical slow wave is referred to the LGN where it modulates the firing of visual relay cells in the laminae and since relay cells do not have local dendritic connections the expansion of a wave of depolarshyizations moving from one relay cell to the next across in the laminar surface will mirror at least in part the expansion of the cortical wave that is spreading contemporaneously through locally-connected cortical cells

PART III RETENTION OF CONSCIOUSNESS

In a normal transition to NREMS the volley of synchronous spindle bursts that marks the onset of stage 2 NREMS overwhelms the normal firing pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 137

of thalamocortical cells preventing their relay of afferent sensory signals and inducing a loss of consciousness21 But the loss of consciousness cannot be timed precisely using cortical EEG the thalamus is too remote for the onset of spindling to be reliably detected by scalp electrodes39 In experiments with cats where electrodes could be implanted in the thalamus researchers found that spindling often reached peak levels of activity in the thalamus-a level of activity consonant with stage 2 NREMS-at a time when the cortical EEG was still showing intermittent desynchronizations a pattern characteristic of the drowsy stage 1 transition not a fully-established stage 2 NREMS episode4o

In other words there is a short period of time in which the synchronous rhythms of stage 2 NREMS are installed in the thalamus but not in the cortex where cortical neurons continue to depolarize in response to afferent sensory signals

T his finding suggests a possible explanation for the authors ability to retain consciousness while spindle bursts are sweeping through the LGN if he is able to extend the duration of this time lag between

the onset of spindling in the thalamus and spindling in the cortex if he is able to stimulate the visual cortices in such a way that they continue to depolarize then he may be able to keep on processing visual signals-to remain visually aware-even after the non-visual thalamus and non-visual cortex become entrained by synchronous sleep rhythms The authors induction technique includes several behaviors which are known to enhance the responsiveness of visual neurons-eye movements attentive fixation and an attitude of expectancy

Effects of eye movements and attention on the LGN Sustained convergence causes periorbital proprioceptors to send excitatory feedback directly to the LGN41 Also convergence further enhances the excitability of geniculate cells by stimulating the superior collicus (SC) which sends its own excitatory signals to the LGN42-43 These signals from the SC are known to selectively enhance the excitability of visual relay cells that represent the periphery of vision44 We know in the authors case that the SC is being stimulated because he is able to keep on fixating an ability which would normally be lost during the transishytion to NREMS45 The ability to fixate can be retained however if the SC is stimulated (even if stimulated during NREMS)46

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 138

Effects of eye movement attention and expectancy on the primary visual cortex The PET study of mental imagery by Kosslyn et al 3 showed that even a baseline resting state of relaxed immobile expectancy can generate signifishycant increases in neuronal activity in the primary visual cortices Further increases can be induced by sustained eye movements

A sustained convergence will release a stream of ponto-geniculo-occipital (PGO) waves These PGO waves called eye movement potentials or EMPs last only as long as the eye movement1747 whereas the PGO waves associated with rapid-eye-movement sleep (REMS) fire continually for the duration of the REMS episode Both REMS-related PGO waves and EMPs have the same desynchronizing effect on the visual pathways they move through the LGN depolarizing the thalamocortical cells which relay the signals to cortical neurons The responsivity of neurons in the primary visual cortices is enhanced by the stimulation of PGO waves 1747-49 If the passage of EMPs causes the genicushylate relay cells and their cortical targets to depolarize regularly then a volley of 4 spindle bursts moving through the same pathways will register as just another series of depolarizations in effect the spindle bursts are processed by the visual system as if they were sensory signals sent from the retina rather than an event stimulated by endogenous mechanisms

T he impact of eye movements and ftxation on the parietal visual cortex Convergence and attentive fixation will also enhance the responsiveness of light-sensitive parietal visual neurons (PVNs) in area PG of the

posterior parietal cortex 50 In experiments where monkeys are trained to fix their attention on a screen-and to keep on fixating even if no targets appearshythe excitability of these light-sensitive PVNs increases by as much as 350 51

52-53Responsiveness is also facilitated by the angle of gaze Also area PG is the first region in the visual pathways containing individual neurons with the capacity to respond to large bilateral stimuli moving in opposite directions along the central meridians of vision (opponent vector motion) 853-55 Facilitation of PVNs in area PG has the effect of sensitizing the subject to bilateral opponent vector motion and this is especially true if the movement appears in the periphery of the VE 8

Intracortical ampliftcation and feedback to the LGN When PGO waves and signals from the SC arrive in the primary visual cortex they may be relatively weak however weak signals can be amplified by reverberating in large networks

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 139

of cortical cells linked by local projection 56 There are nine times as many excitatory links among cortical cells as there are projections from the visual cortex to the LGN an imbalance which suggests leads Suarez Koch and Douglas to propose that geniculate input provides only a minor fraction of the excitatory input the majority originating in neighboring and recurrently connected cortical cells57 If the excitabiliry of cortical neurons is slightly higher than normal then this process of amplification may continue even after the LGN signals that initiated the reverberation are no longer being transmitted by the LGN ( a hysteretic mode of operation) 57

Feedback from hyperexcited cortical neurons will stream back to the LGN via corticogeniculate projections which outnumber geniculocortical projections ten-to-one One effect of this feedback is that the LGN is

able to absorb large amounts of information flowing back from the cortex 58

As signals reverberate back and forth in thalamocorticothalamic circuits a matching process takes place those geniculate relay cells that fire in patterns consistent with the firing patterns of active cortical cells will have their responshysivity enhanced while those geniculate cells that fire in patterns not consistent with cortical cells will be suppressed 59

Preservation of consciousness by selective facilitation of the visual pathways By combining all of the facilitatory effects produced by the authors eye movements and attentive fixation-(l) stimulation of the LGN by feedback from periorbital proprioception both directly and indirectly via the SC (2) the release of PGO waves (EMPs) that facilitate neurons in the LGN and primary visual cortex as they pass (3) the facilitation of the primary visual cortex by a state of relaxed immobile expectancy (4) attentive fixation and angle of gaze that facilitate PVNs in area PG (5) intracortical amplification of signals received from the LGN and (6) corticogeniculate feedback that stimulates the LGN-we delineate a circuit of enhanced excitability that extends from the LGN through the post-geniculate visual heirarchy to area PG where signals are integrated into representations of objects

The hyperexcitability of neurons all along the post-geniculate visual pathways creates conditions in the visual cortices which are similar to those present during EEG-desynchronized states of waking and REMS Therefore neurons in the visual pathways are too excitable to be entrained by synchronous bursting

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 140

patterns when spindle waves move through them instead the spindle bursts stimulate visual neurons to depolarize and then recover as happens in response to afferent sensory signals during waking states It is important to note that for this to occur none of the constituent neuron assemblies is required to perform an abnormal operation the abnormality is a function of the authors intent to activate contemporaneously neuron assemblies that would not normally be co-activated

PART IV HYPNOTIC ANALGESIA

Manipulation of spatial attention as a method for alleviating pain sensations In a theoretical article on the neurophysiology of hypnosis Crawford and Gruzelier60 propose that variations in hypnotizability are function of variability in the efficiency of the frontolimbic (anterior) attentional system in humans high-hypnotizables are better able to sustain focused attention on a task and to ignore extraneous stimuli than are low-hypnotizables

I na related empirical study that compares the use of attention by subjects with high versus low hypnotizability Crawford Brown and Moon61 report that highly hypnotizable persons continue to show physiological reactivity

while cognitively not perceiving the painful stimuli Through disattentional processes they can dissociate themselves from the awareness of pain The authors phosphene induction behaviors-and the cutaneous analgesia he experishyences-appear to involve the same kind of behaviors that is a mobilization of frontolimbic attention used to withdraw attention from external stimuli and to concentrate it on internally-generated phosphene images This suggests the hypothesis that the mechanisms that generate phosphenes might also produce hypnotic analgesia There are several ways that visual signals and pain signals might interact to produce this analgesia

Competition between pain and vision signals for limbic registration The fully-developed sensation of pain requires integration of rwo kinds of informashytion Signals that encode the location and intensity of a noxious stimulus (nociceptive signals) are relayed via the thalamus to the somatosensory cortices which registers only the sensory-discriminative aspects of pain perception62 before reaching consciousness the nociceptive signals must be sent to the limbic

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 141

system where they are linked with signals from long-term memory that encode the affective significance the stimulus has acquired for that individual Studies of brain metabolism show this linking of somatosensory information with limbic associations takes place in the anterior cingulate (CG) and anterior insula62-64

PET studies also show that the anterior CG is activated when subjects shift their spatial attention in response to expectations as to where

66stimuli will next appear65- This is precisely what takes place during the state of immobile expectancy that induces phosphenes Since visual signals and nociceptive signals both require limbic enhancement which is only possible if they get access to the anterior CG there might be conditions in which the two types of afferent sensory signals have to compete for that access In a theoretical article on the mechanisms of attention Posner and Rothbart67

propose that visual signals can interfere with nociceptive signals by blocking access to the anterior CG As behavioral evidence they cite studies showing that when young infants make distress calls they can be distracted by the presentation of a new visual stimulus We have shown the evidence of such control at about three months Orienting to visual events can be employed to quiet or calm negative vocalizations However the distress appears to be maintained and reappears when the infants attention to the stimulus is reduced Caregivers also report the use or visual orienting to block overt manifestations of distress at about this age 67

The effects of disattention on the somatosensory cortices If there is a competition between visual signals and nociceptive signals for access to the anterior CG it is likely that the competition will be affected by the relative volume of signals received A recent study suggests that focusing attention on internally-generated visual stimuli may reduce the number of nociceptive signals relayed by the somatosensory cortices Drevets Burton Videen Snyder Simpson and Raichle68 have shown that the mere anticipation of a touch at a specific cutaneous site increases the flow of blood to those cortical somatosenshysory neurons that are linked with that site where touch is expected and decreases the flow of blood to neurons linked with sites where touch is not expected In this experiment the researchers designated touch as the behaviorally significant sensory stimulus but their findings suggest that the outcome could be reversed if the instructions were reversed if subjects were

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page J42

instructed to direct attention away from a cutaneous site where a noxious stimulus was being applied if they were instructed to relax close their eyes and concentrate on the play of phosphenes in the visual field as the behaviorally significant sensory stimulus then it would be reasonable to expect that the flow of blood would decrease to the somatosensory neurons linked with the cutaneous stimulus and that the flow of blood would increase to the visual cortices The decrease in blood flow to somatosensory neurons implies less neuronal activity which implies that fewer signals are being sent forward to the anterior CG than would have been sent if instead the subject were treating the touch as the behaviorally significant sensory stimulus If fewer pain signals arrive at the anterior it is reasonable to infer that the conscious experience of pain will be muted by the diversion of attention to internal visual stimuli

Differential impact of sleep rhythms in the visual and nonvisual thalamus There is another mechanism that might also contribute to the analgesic effect of inducing sleep rhythms PET studies show that

the thalamus is involved in the relay of nociceptive signals to the cortex63 although some confusion remains about which kinds of signals are relayed by which subregions in the thalamus62 One thalamic site clearly identified by anatomical studies as a relay for nociceptive signals is the ventroposterior lateral nucleus (VPL)69 If synchronous sleep rhythms are active in the thalamus we can reasonably expect that the VPL will itself be entrained by synchronous oscillations and that it will relay the sleep rhythms to somatosensory cortices Relay neurons in the VPL are not stimulated by feedback from eye movements and fixation as are relay neurons in the LGN which suggests that sleep rhythms may impede the relay of nociceptive signals via the VPL but not the relay of visual signals via the LGN

Brain waves associated with anesthesia and NREMS The hypothesis presented here-that consciousness can be preserved despite the presence of NREMS activity-is consistent with a recent report that the kinds of fast brain waves which are normally associated with conscious states are also present during NREMS and anesthesia two states which were thought to involve minimal brain activityJo Another recent study found that there is a close resemblance between the slow brain waves that appear during NREMS and those that appear during certain types of anesthesia71

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 143

bull bull bull

CONCLUSION

In this paper we have presented evidence supporting the hypothesis that phosphene images can be generated as an epiphenomena of thalamic spindle bursts and delta wave activity normally associated with NREMS The prereqshyuisites for inducing these sleep rhythm phosphenes are relaxed immobile expectancy sustained convergence and attentive fixation of an undifferentiated visual field Our hypothesis provides a necessary and sufficient explanation for the authors induction of phosphenes and perhaps also for the generation of phosphenes reported to appear spontaneously during the drowsy transition to sleep (hypnagogic states) during sensory deprivation or during certain kinds of prayer or meditation all of which involve a similar state of relaxed immobile expectancyJ2

CORRESPONDENCE Philip T Nicholson bull 52 Norfolk Road bull Chestnut Hill MA 02167

REFERENCES amp NOTES

1 M 1 Posner Modulation by Instruction Nature 373 (1995) pp 198-199 2 J Reissenweber E David amp M pfotenhauer Investigations of Psychological Aspects of

the Perception of Magnetophosphenes and Electrophosphenes Biomedizinische Tecknik 373 (1992) pp 42-45

3 S M Kosslyn W L Thompson 1 J Kim amp N M Alpert Topographical Representations of Mental Images in Primary Visual Cortex Nature 378 (I995) pp 496-498

4 P E Roland amp B Gulyas Visual Memory Visual Imagery and Visual Recognition of Large Field Patterns by the Human Brain Functional Anatomy by Positron Emission Tomography Cerebral Cortex 51 (1995) pp 79-93

5 H Benson The Relaxation Response (Morrow New York NY 1975) 6 ] H Schultz amp W Luthe Autogenic Training a Physiological Approach to Psychotherapy

(Grune amp Stratton New York NY 1969) 7 E Jacobson Progressive Relaxation (University of Chicago Press Chicago IL 1938) 8 M A Steinmetz BC Motter C] DuffY amp V B Mountcastle Functional Properties

of Parietal Visual Neurons Radial Organization of Directionalities Within the Visual Field Journal ofNeuroscience 71 (1987) pp 177-191

9 R R Edelman Magnetic Resonance Imaging of the Nervous System Discussions in Neuroscience 71 Elsevier Science Amsterdam (I990) also J H Newhouse amp ] I Wiener Understanding MRI 1st Ed (Little Brown Boston MA 1991)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 144

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

A REPRESENTATION OF THE VISUAL FIELD IN EACH LAMINA

orooqUtftc O-u OCIJ1SALfIOLI (I01flAj

0

10

20

30

40 n50 Of

60

70

20 loO 1Mgr_ II~ o UIpoundAS65 mn1MY-o actlvncL ~~~r

Jll-COMcetlImiddot~

II LAYERSU 3 GatQYancetl~ (1) ucon ceom-oyenF (2)l~cen()FF 3) ~ cenloH

II~ cng1loqctWIIIfNla

iICINe -- (t81Otdb1t1d~OH (2)~

80

B CONE SPECTRAL SENSITIVITY CURVES

S-COHS

WAVIlLllNG1llS OF UGHT IH NANOMllTERS (NM)

Figure 5 Phosphene color as a function of ganglion cell distribution in parvocellular laminae (Aj Schematic drawing ofthe proportion ofthe VF represented in each laminae The proportions shown here are based on the work of Connolly and Van Essen24 The

far periphery of vision (50 0 to 80 0 of isoeccentricity) is represented in only two laminae-laminae 1 and 6-and of these two only lamina 6 is a parvocelLular lamina capable ofencoding wavelength signals Therefore only those wavelengths relayed by lamina 6 will participate in forming a cortical lighmess record for the far periphery of the VP (B) Cone spectral sensitivity curves (adapted from Marks et al)36 Using these cone sensitivity curves we can estimate the sensation stimulated by a spindle wave moving through lamina 6 by averaging the wavelengths that elicit maximal responses for M-cones (535 nanomeshyters) and L-cones (520 nm) which yields a mean wavelength value of550 nm In humans this generates a sensation of green or yellow-green the sensation observed by the author when the receding annulus enters at the far periphery of the VP For a calculation of the cortical lightness record when a spindle wave moves through 20deg to 0deg ofthe VF stimulating all 4 parvocelfular laminae see the text and Figure 6

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 133

Once the spindle wave penetrates to laminae 3 and 4 it may activate all 4 parvocellular laminae stimulating TC cells to send contradictory wavelength signals for the same retinotopic location the signals sent from laminae 4 and 3 will encode blue light (S-cone center-ON plus M-cone center-OFF and Lshycone center-OFF) while the signals sent from laminae 5 and 6 encode yellowshygreen light (M-cone center-ON plus L-cone center-ON) This kind of contrashydiction does not occur in normal retina-based perception where light energy striking the retina is structured by the retinas center-surround and colorshyopponent organization to encode only one set of wavelength signals for each spatial locus 32 In Figure 6 we estimate the cortical lightness record that results when contradictory wavelength signals compete to be represented in consciousshyness Our calculations suggest that the outcome will be a mean wavelength which in humans elicits a dark blue or violet sensation

PART II AMORPHOUS PHOSPHENES amp THALAMIC DELTA ACTMTY

M echanisms controlling the transition from spindle bursts to delta activity In the consensus scenario for the generation of NREMS16-20 we noted that the RTN shifts to firing spindle bursts

when polarization of thalamic cell membranes drops to V m = - 60 mV At the same time cortical cells begin oscillating with a synchronous slow rhythm laquo 1 Hz) Both processes further decrease the Vm of TC cell membranes When Vm = - 75 mY TC cells begin to generate their own intrinsic calcium currents which also decreases V m At V m = - 90 mV RTN neurons stop firing spindle bursts At the same time the TC cells begin firing low-threshold calcium spikes in alternation with after-hyperpolarizations (LTS-AHP) Because sensory relay neurons in the LGN are not linked to one another by locally projecting axons the firing of one TC cell does not excite its neighbor However a lack of local connectivity does not mean that TC cells occupying the same laminae release their AHP-LTS calcium spikes in a random distribshyution rather spikes are released simultaneously by groups of cells in synchrony with the advent of the cortical slow wave In effect the distribution of LTSshyAHP spikes firing in the LGN is determined by the spatial propagation of the cortical slow wave Thus the delta wave (1 to 4 Hz) activity detected by cortical EEG during NREMS is a product of the interaction between the AHP-LTS calcium spikes released by TC cells and the cortical slow rhythm

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 134

CORTICAL PROCESSING OF CONTRADICTORY

WAVELENGTH SIGNALS

KEY _ Cells firing

cJ Cononol firing

Assume that as a spind6e wave moves through the LGNlt fires simultaneously aU the TC cells that represent a particular reUnoshytopic locus (x y) in each of the six laminae As a result cortical cells engaged In the higher level processing of visual signals will receive more wavelength signals representing retina locus (x y) than are generated by normal perception laquo and some of these afferent wavelength signals may contradict other signals arriving simultaneously

CORTICAL LIGHTNESS RECORD SlgnalSell

Intemal contradictions not congruent wilt pre

SmiddotON eristing neuron neta

s bullbull M-ON LmiddotON

3 bullbull M-OFF + L-OFF

a-ON 12

ROD-ON

No Internal eonlradlemiddot

--------1I =~8b~~~~~~~t signals

3+4

~ --OFF Excludes 6 Of 7 $J9n18

1+2 B-ON I

IWmiddotHmiddotI Signal Sell

1111111 No Intern1 conlrfldlcshy lion

Exelvdta 4 out of 7 efshy

bullbullbull bullbullbull ferant signals

No Intern1 contradic_ tionnee S-ON BshyOH and ROO-ON can all be coacllve at low lImlnance levels nef Ihe rod-eone break

ExchJde$ only 2 Ollt of 7 afferent signals

Figure 6 Selection of competing wavelength signals based on neuronal group selection This thought experiment is based on Edelman sconcept ofneuronal group selection 73 We assume that all possible combinations ofsignals will form sets and that all signal-sets will compete to make the most efficient match with pre-existing neuromd networks that have been forged over years ofnorma reti1U1-based perception We also assume that pre-existing neural networks are most likely to expedite those sets that satisfY 2 criteriI (J) the signals in a set do not contradict each other and (2) fower signals are excluded than in the other sets that satisfY the first criterion In our analysis Set 4 wins the competition because it does not contain internal contradictions and excludes fower signals (2 out of 7) than Set 3 excludes (4 out of7) It is not an internal contradiction that Set 4 contains both rods and cone Signtlls in normal retina-based perception when luminance levels approach the rod-cone break S-cone center-ON receptors send signas as do rod receptors and there is even evidence that rod activity may actually drive S-cone activity even after luminance levels foIl below the rod-cone break74 To calculate the cortical lightness record for Set 4 we average the wavelength that elicits maximal responses foom rods (511 nm) and for Sshycones (430 nm) which yields a mean wavelength of 470 nm which in humans results in a dark-blue or violet sensation

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 135

The cortical slow rhythm is an example of a generic pattern of neuronal excitashytion that occurs in large networks of neurons linked by local projections A recent experiment by Maeda Robinson and Kwana38 shows that networks of locally-connected neurons spontaneously generate periodic synchronized bursts of calcium transients that propagate across the network in an expanding spatial wave a pattern that represents a stable mode of firing towards which these neuronal networks relax following perturbations for example by electronic stimulation or by drugs Understanding the characteristics of these waves is an important prerequisite to understanding the mechanisms that produce the amorphous phosphene images as a visual epiphenomenon

To study the spontaneous periodic synchronized bursts the researchers prepared cultures of dissociated cortical neurons and allowed them to mature for several days in vitro (DIV) After 3 to 4 DIV when concenshy

trations of extracellular magnesium were low electrodes began to detect spontaneous synchronized bursts of low frequency calcium transients (between 01 and 1 Hz) that originated in different locations on the sheet every 10 to 20 seconds and spread across the sheet of cells at a relatively slow speed averaging 50 mmsecond The researchers could not predict where a wave would originate or where it would expand rather the initiation and expansion of waves was generated by spatial and temporal summation of a continuous random background of synaptic inputs including miniature spontaneous synaptic events but the pattern was not random since waves propagated sequentially from electrode to electrode as each local group of neurons charges up its neighboring nontefractory areas rather than in a random sequence of regions38

The excitability of the cells in the sheet determines the probability first that there will be a synchronous burst and second that it will spread in a particshyular direction Cells become more excitable as the cultures mature which means the refractory intervals between successive bursts were much shorter in mature cultures (gt 30 DIV) than in early cultures laquo 7 DIV) Some cells became so insensitive to inhibition that they continued to fire bursts even when extracellular concentrations of magnesium were relatively high Finally there were refractory periods of 5 to 10 seconds during which no bursts occurred even when an electrical stimulus was applied This refractory interval for cultured networks is slightly longer than the refractory interval observed of the cortical slow wave in vivo which 25 to 4 seconds 18- 19

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 136

Based on the observations about cortical slow waves we can predict that phosphenes generated as epiphenomena of delta wave activity will present the following signal characteristics (1) signals that appear at unpredictable locations in the VF (2) signals that expand and diverge asymmetrically following unpredictable trajectories which may encompass large areas of the VF (3) signals that move relatively slowly (50 mmsec) (4) signals that recur with a period of 2 to 4 seconds reflecting entrainment by the cortical slow wave (5) signals that do not terminate automatically after a predictable number of cycles

The spatial patterns of phosphene mists and thalamic delta waves are similar The spatiotemporal characteristics of amorphous phosphenes match the pattern of wave propagation associated with periodic spontashy

neous synchronized bursts in large neuron networks the amorphous phosphenes enter the visual field at unpredictable locations expand and diverge asymmetrically with a slow steady rate of flow follow trajectories that are unpredictable and exhibit a refractory interval The amorphous mists do appear to have a periodicity although the author is unable to sustain the vision while also counting the seconds therefore he is unable to determine if it compares to the period of the cortical slow wave (25 to 4 seconds) but his impression is that it feels roughly the same as as with receding annuli which recur at 5 seconds Also the refractory interval feels as if it decreases as the induction session is extended These similarities suggest that the amorphous phosphenes are generated by stage 2 NREMS delta wave activity which is an activity governed by the reverberation of the cortical slow wave in thalamoshycorticothalamic circuits The cortical slow wave is referred to the LGN where it modulates the firing of visual relay cells in the laminae and since relay cells do not have local dendritic connections the expansion of a wave of depolarshyizations moving from one relay cell to the next across in the laminar surface will mirror at least in part the expansion of the cortical wave that is spreading contemporaneously through locally-connected cortical cells

PART III RETENTION OF CONSCIOUSNESS

In a normal transition to NREMS the volley of synchronous spindle bursts that marks the onset of stage 2 NREMS overwhelms the normal firing pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 137

of thalamocortical cells preventing their relay of afferent sensory signals and inducing a loss of consciousness21 But the loss of consciousness cannot be timed precisely using cortical EEG the thalamus is too remote for the onset of spindling to be reliably detected by scalp electrodes39 In experiments with cats where electrodes could be implanted in the thalamus researchers found that spindling often reached peak levels of activity in the thalamus-a level of activity consonant with stage 2 NREMS-at a time when the cortical EEG was still showing intermittent desynchronizations a pattern characteristic of the drowsy stage 1 transition not a fully-established stage 2 NREMS episode4o

In other words there is a short period of time in which the synchronous rhythms of stage 2 NREMS are installed in the thalamus but not in the cortex where cortical neurons continue to depolarize in response to afferent sensory signals

T his finding suggests a possible explanation for the authors ability to retain consciousness while spindle bursts are sweeping through the LGN if he is able to extend the duration of this time lag between

the onset of spindling in the thalamus and spindling in the cortex if he is able to stimulate the visual cortices in such a way that they continue to depolarize then he may be able to keep on processing visual signals-to remain visually aware-even after the non-visual thalamus and non-visual cortex become entrained by synchronous sleep rhythms The authors induction technique includes several behaviors which are known to enhance the responsiveness of visual neurons-eye movements attentive fixation and an attitude of expectancy

Effects of eye movements and attention on the LGN Sustained convergence causes periorbital proprioceptors to send excitatory feedback directly to the LGN41 Also convergence further enhances the excitability of geniculate cells by stimulating the superior collicus (SC) which sends its own excitatory signals to the LGN42-43 These signals from the SC are known to selectively enhance the excitability of visual relay cells that represent the periphery of vision44 We know in the authors case that the SC is being stimulated because he is able to keep on fixating an ability which would normally be lost during the transishytion to NREMS45 The ability to fixate can be retained however if the SC is stimulated (even if stimulated during NREMS)46

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 138

Effects of eye movement attention and expectancy on the primary visual cortex The PET study of mental imagery by Kosslyn et al 3 showed that even a baseline resting state of relaxed immobile expectancy can generate signifishycant increases in neuronal activity in the primary visual cortices Further increases can be induced by sustained eye movements

A sustained convergence will release a stream of ponto-geniculo-occipital (PGO) waves These PGO waves called eye movement potentials or EMPs last only as long as the eye movement1747 whereas the PGO waves associated with rapid-eye-movement sleep (REMS) fire continually for the duration of the REMS episode Both REMS-related PGO waves and EMPs have the same desynchronizing effect on the visual pathways they move through the LGN depolarizing the thalamocortical cells which relay the signals to cortical neurons The responsivity of neurons in the primary visual cortices is enhanced by the stimulation of PGO waves 1747-49 If the passage of EMPs causes the genicushylate relay cells and their cortical targets to depolarize regularly then a volley of 4 spindle bursts moving through the same pathways will register as just another series of depolarizations in effect the spindle bursts are processed by the visual system as if they were sensory signals sent from the retina rather than an event stimulated by endogenous mechanisms

T he impact of eye movements and ftxation on the parietal visual cortex Convergence and attentive fixation will also enhance the responsiveness of light-sensitive parietal visual neurons (PVNs) in area PG of the

posterior parietal cortex 50 In experiments where monkeys are trained to fix their attention on a screen-and to keep on fixating even if no targets appearshythe excitability of these light-sensitive PVNs increases by as much as 350 51

52-53Responsiveness is also facilitated by the angle of gaze Also area PG is the first region in the visual pathways containing individual neurons with the capacity to respond to large bilateral stimuli moving in opposite directions along the central meridians of vision (opponent vector motion) 853-55 Facilitation of PVNs in area PG has the effect of sensitizing the subject to bilateral opponent vector motion and this is especially true if the movement appears in the periphery of the VE 8

Intracortical ampliftcation and feedback to the LGN When PGO waves and signals from the SC arrive in the primary visual cortex they may be relatively weak however weak signals can be amplified by reverberating in large networks

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 139

of cortical cells linked by local projection 56 There are nine times as many excitatory links among cortical cells as there are projections from the visual cortex to the LGN an imbalance which suggests leads Suarez Koch and Douglas to propose that geniculate input provides only a minor fraction of the excitatory input the majority originating in neighboring and recurrently connected cortical cells57 If the excitabiliry of cortical neurons is slightly higher than normal then this process of amplification may continue even after the LGN signals that initiated the reverberation are no longer being transmitted by the LGN ( a hysteretic mode of operation) 57

Feedback from hyperexcited cortical neurons will stream back to the LGN via corticogeniculate projections which outnumber geniculocortical projections ten-to-one One effect of this feedback is that the LGN is

able to absorb large amounts of information flowing back from the cortex 58

As signals reverberate back and forth in thalamocorticothalamic circuits a matching process takes place those geniculate relay cells that fire in patterns consistent with the firing patterns of active cortical cells will have their responshysivity enhanced while those geniculate cells that fire in patterns not consistent with cortical cells will be suppressed 59

Preservation of consciousness by selective facilitation of the visual pathways By combining all of the facilitatory effects produced by the authors eye movements and attentive fixation-(l) stimulation of the LGN by feedback from periorbital proprioception both directly and indirectly via the SC (2) the release of PGO waves (EMPs) that facilitate neurons in the LGN and primary visual cortex as they pass (3) the facilitation of the primary visual cortex by a state of relaxed immobile expectancy (4) attentive fixation and angle of gaze that facilitate PVNs in area PG (5) intracortical amplification of signals received from the LGN and (6) corticogeniculate feedback that stimulates the LGN-we delineate a circuit of enhanced excitability that extends from the LGN through the post-geniculate visual heirarchy to area PG where signals are integrated into representations of objects

The hyperexcitability of neurons all along the post-geniculate visual pathways creates conditions in the visual cortices which are similar to those present during EEG-desynchronized states of waking and REMS Therefore neurons in the visual pathways are too excitable to be entrained by synchronous bursting

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 140

patterns when spindle waves move through them instead the spindle bursts stimulate visual neurons to depolarize and then recover as happens in response to afferent sensory signals during waking states It is important to note that for this to occur none of the constituent neuron assemblies is required to perform an abnormal operation the abnormality is a function of the authors intent to activate contemporaneously neuron assemblies that would not normally be co-activated

PART IV HYPNOTIC ANALGESIA

Manipulation of spatial attention as a method for alleviating pain sensations In a theoretical article on the neurophysiology of hypnosis Crawford and Gruzelier60 propose that variations in hypnotizability are function of variability in the efficiency of the frontolimbic (anterior) attentional system in humans high-hypnotizables are better able to sustain focused attention on a task and to ignore extraneous stimuli than are low-hypnotizables

I na related empirical study that compares the use of attention by subjects with high versus low hypnotizability Crawford Brown and Moon61 report that highly hypnotizable persons continue to show physiological reactivity

while cognitively not perceiving the painful stimuli Through disattentional processes they can dissociate themselves from the awareness of pain The authors phosphene induction behaviors-and the cutaneous analgesia he experishyences-appear to involve the same kind of behaviors that is a mobilization of frontolimbic attention used to withdraw attention from external stimuli and to concentrate it on internally-generated phosphene images This suggests the hypothesis that the mechanisms that generate phosphenes might also produce hypnotic analgesia There are several ways that visual signals and pain signals might interact to produce this analgesia

Competition between pain and vision signals for limbic registration The fully-developed sensation of pain requires integration of rwo kinds of informashytion Signals that encode the location and intensity of a noxious stimulus (nociceptive signals) are relayed via the thalamus to the somatosensory cortices which registers only the sensory-discriminative aspects of pain perception62 before reaching consciousness the nociceptive signals must be sent to the limbic

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 141

system where they are linked with signals from long-term memory that encode the affective significance the stimulus has acquired for that individual Studies of brain metabolism show this linking of somatosensory information with limbic associations takes place in the anterior cingulate (CG) and anterior insula62-64

PET studies also show that the anterior CG is activated when subjects shift their spatial attention in response to expectations as to where

66stimuli will next appear65- This is precisely what takes place during the state of immobile expectancy that induces phosphenes Since visual signals and nociceptive signals both require limbic enhancement which is only possible if they get access to the anterior CG there might be conditions in which the two types of afferent sensory signals have to compete for that access In a theoretical article on the mechanisms of attention Posner and Rothbart67

propose that visual signals can interfere with nociceptive signals by blocking access to the anterior CG As behavioral evidence they cite studies showing that when young infants make distress calls they can be distracted by the presentation of a new visual stimulus We have shown the evidence of such control at about three months Orienting to visual events can be employed to quiet or calm negative vocalizations However the distress appears to be maintained and reappears when the infants attention to the stimulus is reduced Caregivers also report the use or visual orienting to block overt manifestations of distress at about this age 67

The effects of disattention on the somatosensory cortices If there is a competition between visual signals and nociceptive signals for access to the anterior CG it is likely that the competition will be affected by the relative volume of signals received A recent study suggests that focusing attention on internally-generated visual stimuli may reduce the number of nociceptive signals relayed by the somatosensory cortices Drevets Burton Videen Snyder Simpson and Raichle68 have shown that the mere anticipation of a touch at a specific cutaneous site increases the flow of blood to those cortical somatosenshysory neurons that are linked with that site where touch is expected and decreases the flow of blood to neurons linked with sites where touch is not expected In this experiment the researchers designated touch as the behaviorally significant sensory stimulus but their findings suggest that the outcome could be reversed if the instructions were reversed if subjects were

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page J42

instructed to direct attention away from a cutaneous site where a noxious stimulus was being applied if they were instructed to relax close their eyes and concentrate on the play of phosphenes in the visual field as the behaviorally significant sensory stimulus then it would be reasonable to expect that the flow of blood would decrease to the somatosensory neurons linked with the cutaneous stimulus and that the flow of blood would increase to the visual cortices The decrease in blood flow to somatosensory neurons implies less neuronal activity which implies that fewer signals are being sent forward to the anterior CG than would have been sent if instead the subject were treating the touch as the behaviorally significant sensory stimulus If fewer pain signals arrive at the anterior it is reasonable to infer that the conscious experience of pain will be muted by the diversion of attention to internal visual stimuli

Differential impact of sleep rhythms in the visual and nonvisual thalamus There is another mechanism that might also contribute to the analgesic effect of inducing sleep rhythms PET studies show that

the thalamus is involved in the relay of nociceptive signals to the cortex63 although some confusion remains about which kinds of signals are relayed by which subregions in the thalamus62 One thalamic site clearly identified by anatomical studies as a relay for nociceptive signals is the ventroposterior lateral nucleus (VPL)69 If synchronous sleep rhythms are active in the thalamus we can reasonably expect that the VPL will itself be entrained by synchronous oscillations and that it will relay the sleep rhythms to somatosensory cortices Relay neurons in the VPL are not stimulated by feedback from eye movements and fixation as are relay neurons in the LGN which suggests that sleep rhythms may impede the relay of nociceptive signals via the VPL but not the relay of visual signals via the LGN

Brain waves associated with anesthesia and NREMS The hypothesis presented here-that consciousness can be preserved despite the presence of NREMS activity-is consistent with a recent report that the kinds of fast brain waves which are normally associated with conscious states are also present during NREMS and anesthesia two states which were thought to involve minimal brain activityJo Another recent study found that there is a close resemblance between the slow brain waves that appear during NREMS and those that appear during certain types of anesthesia71

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 143

bull bull bull

CONCLUSION

In this paper we have presented evidence supporting the hypothesis that phosphene images can be generated as an epiphenomena of thalamic spindle bursts and delta wave activity normally associated with NREMS The prereqshyuisites for inducing these sleep rhythm phosphenes are relaxed immobile expectancy sustained convergence and attentive fixation of an undifferentiated visual field Our hypothesis provides a necessary and sufficient explanation for the authors induction of phosphenes and perhaps also for the generation of phosphenes reported to appear spontaneously during the drowsy transition to sleep (hypnagogic states) during sensory deprivation or during certain kinds of prayer or meditation all of which involve a similar state of relaxed immobile expectancyJ2

CORRESPONDENCE Philip T Nicholson bull 52 Norfolk Road bull Chestnut Hill MA 02167

REFERENCES amp NOTES

1 M 1 Posner Modulation by Instruction Nature 373 (1995) pp 198-199 2 J Reissenweber E David amp M pfotenhauer Investigations of Psychological Aspects of

the Perception of Magnetophosphenes and Electrophosphenes Biomedizinische Tecknik 373 (1992) pp 42-45

3 S M Kosslyn W L Thompson 1 J Kim amp N M Alpert Topographical Representations of Mental Images in Primary Visual Cortex Nature 378 (I995) pp 496-498

4 P E Roland amp B Gulyas Visual Memory Visual Imagery and Visual Recognition of Large Field Patterns by the Human Brain Functional Anatomy by Positron Emission Tomography Cerebral Cortex 51 (1995) pp 79-93

5 H Benson The Relaxation Response (Morrow New York NY 1975) 6 ] H Schultz amp W Luthe Autogenic Training a Physiological Approach to Psychotherapy

(Grune amp Stratton New York NY 1969) 7 E Jacobson Progressive Relaxation (University of Chicago Press Chicago IL 1938) 8 M A Steinmetz BC Motter C] DuffY amp V B Mountcastle Functional Properties

of Parietal Visual Neurons Radial Organization of Directionalities Within the Visual Field Journal ofNeuroscience 71 (1987) pp 177-191

9 R R Edelman Magnetic Resonance Imaging of the Nervous System Discussions in Neuroscience 71 Elsevier Science Amsterdam (I990) also J H Newhouse amp ] I Wiener Understanding MRI 1st Ed (Little Brown Boston MA 1991)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 144

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

Once the spindle wave penetrates to laminae 3 and 4 it may activate all 4 parvocellular laminae stimulating TC cells to send contradictory wavelength signals for the same retinotopic location the signals sent from laminae 4 and 3 will encode blue light (S-cone center-ON plus M-cone center-OFF and Lshycone center-OFF) while the signals sent from laminae 5 and 6 encode yellowshygreen light (M-cone center-ON plus L-cone center-ON) This kind of contrashydiction does not occur in normal retina-based perception where light energy striking the retina is structured by the retinas center-surround and colorshyopponent organization to encode only one set of wavelength signals for each spatial locus 32 In Figure 6 we estimate the cortical lightness record that results when contradictory wavelength signals compete to be represented in consciousshyness Our calculations suggest that the outcome will be a mean wavelength which in humans elicits a dark blue or violet sensation

PART II AMORPHOUS PHOSPHENES amp THALAMIC DELTA ACTMTY

M echanisms controlling the transition from spindle bursts to delta activity In the consensus scenario for the generation of NREMS16-20 we noted that the RTN shifts to firing spindle bursts

when polarization of thalamic cell membranes drops to V m = - 60 mV At the same time cortical cells begin oscillating with a synchronous slow rhythm laquo 1 Hz) Both processes further decrease the Vm of TC cell membranes When Vm = - 75 mY TC cells begin to generate their own intrinsic calcium currents which also decreases V m At V m = - 90 mV RTN neurons stop firing spindle bursts At the same time the TC cells begin firing low-threshold calcium spikes in alternation with after-hyperpolarizations (LTS-AHP) Because sensory relay neurons in the LGN are not linked to one another by locally projecting axons the firing of one TC cell does not excite its neighbor However a lack of local connectivity does not mean that TC cells occupying the same laminae release their AHP-LTS calcium spikes in a random distribshyution rather spikes are released simultaneously by groups of cells in synchrony with the advent of the cortical slow wave In effect the distribution of LTSshyAHP spikes firing in the LGN is determined by the spatial propagation of the cortical slow wave Thus the delta wave (1 to 4 Hz) activity detected by cortical EEG during NREMS is a product of the interaction between the AHP-LTS calcium spikes released by TC cells and the cortical slow rhythm

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 134

CORTICAL PROCESSING OF CONTRADICTORY

WAVELENGTH SIGNALS

KEY _ Cells firing

cJ Cononol firing

Assume that as a spind6e wave moves through the LGNlt fires simultaneously aU the TC cells that represent a particular reUnoshytopic locus (x y) in each of the six laminae As a result cortical cells engaged In the higher level processing of visual signals will receive more wavelength signals representing retina locus (x y) than are generated by normal perception laquo and some of these afferent wavelength signals may contradict other signals arriving simultaneously

CORTICAL LIGHTNESS RECORD SlgnalSell

Intemal contradictions not congruent wilt pre

SmiddotON eristing neuron neta

s bullbull M-ON LmiddotON

3 bullbull M-OFF + L-OFF

a-ON 12

ROD-ON

No Internal eonlradlemiddot

--------1I =~8b~~~~~~~t signals

3+4

~ --OFF Excludes 6 Of 7 $J9n18

1+2 B-ON I

IWmiddotHmiddotI Signal Sell

1111111 No Intern1 conlrfldlcshy lion

Exelvdta 4 out of 7 efshy

bullbullbull bullbullbull ferant signals

No Intern1 contradic_ tionnee S-ON BshyOH and ROO-ON can all be coacllve at low lImlnance levels nef Ihe rod-eone break

ExchJde$ only 2 Ollt of 7 afferent signals

Figure 6 Selection of competing wavelength signals based on neuronal group selection This thought experiment is based on Edelman sconcept ofneuronal group selection 73 We assume that all possible combinations ofsignals will form sets and that all signal-sets will compete to make the most efficient match with pre-existing neuromd networks that have been forged over years ofnorma reti1U1-based perception We also assume that pre-existing neural networks are most likely to expedite those sets that satisfY 2 criteriI (J) the signals in a set do not contradict each other and (2) fower signals are excluded than in the other sets that satisfY the first criterion In our analysis Set 4 wins the competition because it does not contain internal contradictions and excludes fower signals (2 out of 7) than Set 3 excludes (4 out of7) It is not an internal contradiction that Set 4 contains both rods and cone Signtlls in normal retina-based perception when luminance levels approach the rod-cone break S-cone center-ON receptors send signas as do rod receptors and there is even evidence that rod activity may actually drive S-cone activity even after luminance levels foIl below the rod-cone break74 To calculate the cortical lightness record for Set 4 we average the wavelength that elicits maximal responses foom rods (511 nm) and for Sshycones (430 nm) which yields a mean wavelength of 470 nm which in humans results in a dark-blue or violet sensation

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 135

The cortical slow rhythm is an example of a generic pattern of neuronal excitashytion that occurs in large networks of neurons linked by local projections A recent experiment by Maeda Robinson and Kwana38 shows that networks of locally-connected neurons spontaneously generate periodic synchronized bursts of calcium transients that propagate across the network in an expanding spatial wave a pattern that represents a stable mode of firing towards which these neuronal networks relax following perturbations for example by electronic stimulation or by drugs Understanding the characteristics of these waves is an important prerequisite to understanding the mechanisms that produce the amorphous phosphene images as a visual epiphenomenon

To study the spontaneous periodic synchronized bursts the researchers prepared cultures of dissociated cortical neurons and allowed them to mature for several days in vitro (DIV) After 3 to 4 DIV when concenshy

trations of extracellular magnesium were low electrodes began to detect spontaneous synchronized bursts of low frequency calcium transients (between 01 and 1 Hz) that originated in different locations on the sheet every 10 to 20 seconds and spread across the sheet of cells at a relatively slow speed averaging 50 mmsecond The researchers could not predict where a wave would originate or where it would expand rather the initiation and expansion of waves was generated by spatial and temporal summation of a continuous random background of synaptic inputs including miniature spontaneous synaptic events but the pattern was not random since waves propagated sequentially from electrode to electrode as each local group of neurons charges up its neighboring nontefractory areas rather than in a random sequence of regions38

The excitability of the cells in the sheet determines the probability first that there will be a synchronous burst and second that it will spread in a particshyular direction Cells become more excitable as the cultures mature which means the refractory intervals between successive bursts were much shorter in mature cultures (gt 30 DIV) than in early cultures laquo 7 DIV) Some cells became so insensitive to inhibition that they continued to fire bursts even when extracellular concentrations of magnesium were relatively high Finally there were refractory periods of 5 to 10 seconds during which no bursts occurred even when an electrical stimulus was applied This refractory interval for cultured networks is slightly longer than the refractory interval observed of the cortical slow wave in vivo which 25 to 4 seconds 18- 19

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 136

Based on the observations about cortical slow waves we can predict that phosphenes generated as epiphenomena of delta wave activity will present the following signal characteristics (1) signals that appear at unpredictable locations in the VF (2) signals that expand and diverge asymmetrically following unpredictable trajectories which may encompass large areas of the VF (3) signals that move relatively slowly (50 mmsec) (4) signals that recur with a period of 2 to 4 seconds reflecting entrainment by the cortical slow wave (5) signals that do not terminate automatically after a predictable number of cycles

The spatial patterns of phosphene mists and thalamic delta waves are similar The spatiotemporal characteristics of amorphous phosphenes match the pattern of wave propagation associated with periodic spontashy

neous synchronized bursts in large neuron networks the amorphous phosphenes enter the visual field at unpredictable locations expand and diverge asymmetrically with a slow steady rate of flow follow trajectories that are unpredictable and exhibit a refractory interval The amorphous mists do appear to have a periodicity although the author is unable to sustain the vision while also counting the seconds therefore he is unable to determine if it compares to the period of the cortical slow wave (25 to 4 seconds) but his impression is that it feels roughly the same as as with receding annuli which recur at 5 seconds Also the refractory interval feels as if it decreases as the induction session is extended These similarities suggest that the amorphous phosphenes are generated by stage 2 NREMS delta wave activity which is an activity governed by the reverberation of the cortical slow wave in thalamoshycorticothalamic circuits The cortical slow wave is referred to the LGN where it modulates the firing of visual relay cells in the laminae and since relay cells do not have local dendritic connections the expansion of a wave of depolarshyizations moving from one relay cell to the next across in the laminar surface will mirror at least in part the expansion of the cortical wave that is spreading contemporaneously through locally-connected cortical cells

PART III RETENTION OF CONSCIOUSNESS

In a normal transition to NREMS the volley of synchronous spindle bursts that marks the onset of stage 2 NREMS overwhelms the normal firing pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 137

of thalamocortical cells preventing their relay of afferent sensory signals and inducing a loss of consciousness21 But the loss of consciousness cannot be timed precisely using cortical EEG the thalamus is too remote for the onset of spindling to be reliably detected by scalp electrodes39 In experiments with cats where electrodes could be implanted in the thalamus researchers found that spindling often reached peak levels of activity in the thalamus-a level of activity consonant with stage 2 NREMS-at a time when the cortical EEG was still showing intermittent desynchronizations a pattern characteristic of the drowsy stage 1 transition not a fully-established stage 2 NREMS episode4o

In other words there is a short period of time in which the synchronous rhythms of stage 2 NREMS are installed in the thalamus but not in the cortex where cortical neurons continue to depolarize in response to afferent sensory signals

T his finding suggests a possible explanation for the authors ability to retain consciousness while spindle bursts are sweeping through the LGN if he is able to extend the duration of this time lag between

the onset of spindling in the thalamus and spindling in the cortex if he is able to stimulate the visual cortices in such a way that they continue to depolarize then he may be able to keep on processing visual signals-to remain visually aware-even after the non-visual thalamus and non-visual cortex become entrained by synchronous sleep rhythms The authors induction technique includes several behaviors which are known to enhance the responsiveness of visual neurons-eye movements attentive fixation and an attitude of expectancy

Effects of eye movements and attention on the LGN Sustained convergence causes periorbital proprioceptors to send excitatory feedback directly to the LGN41 Also convergence further enhances the excitability of geniculate cells by stimulating the superior collicus (SC) which sends its own excitatory signals to the LGN42-43 These signals from the SC are known to selectively enhance the excitability of visual relay cells that represent the periphery of vision44 We know in the authors case that the SC is being stimulated because he is able to keep on fixating an ability which would normally be lost during the transishytion to NREMS45 The ability to fixate can be retained however if the SC is stimulated (even if stimulated during NREMS)46

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 138

Effects of eye movement attention and expectancy on the primary visual cortex The PET study of mental imagery by Kosslyn et al 3 showed that even a baseline resting state of relaxed immobile expectancy can generate signifishycant increases in neuronal activity in the primary visual cortices Further increases can be induced by sustained eye movements

A sustained convergence will release a stream of ponto-geniculo-occipital (PGO) waves These PGO waves called eye movement potentials or EMPs last only as long as the eye movement1747 whereas the PGO waves associated with rapid-eye-movement sleep (REMS) fire continually for the duration of the REMS episode Both REMS-related PGO waves and EMPs have the same desynchronizing effect on the visual pathways they move through the LGN depolarizing the thalamocortical cells which relay the signals to cortical neurons The responsivity of neurons in the primary visual cortices is enhanced by the stimulation of PGO waves 1747-49 If the passage of EMPs causes the genicushylate relay cells and their cortical targets to depolarize regularly then a volley of 4 spindle bursts moving through the same pathways will register as just another series of depolarizations in effect the spindle bursts are processed by the visual system as if they were sensory signals sent from the retina rather than an event stimulated by endogenous mechanisms

T he impact of eye movements and ftxation on the parietal visual cortex Convergence and attentive fixation will also enhance the responsiveness of light-sensitive parietal visual neurons (PVNs) in area PG of the

posterior parietal cortex 50 In experiments where monkeys are trained to fix their attention on a screen-and to keep on fixating even if no targets appearshythe excitability of these light-sensitive PVNs increases by as much as 350 51

52-53Responsiveness is also facilitated by the angle of gaze Also area PG is the first region in the visual pathways containing individual neurons with the capacity to respond to large bilateral stimuli moving in opposite directions along the central meridians of vision (opponent vector motion) 853-55 Facilitation of PVNs in area PG has the effect of sensitizing the subject to bilateral opponent vector motion and this is especially true if the movement appears in the periphery of the VE 8

Intracortical ampliftcation and feedback to the LGN When PGO waves and signals from the SC arrive in the primary visual cortex they may be relatively weak however weak signals can be amplified by reverberating in large networks

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 139

of cortical cells linked by local projection 56 There are nine times as many excitatory links among cortical cells as there are projections from the visual cortex to the LGN an imbalance which suggests leads Suarez Koch and Douglas to propose that geniculate input provides only a minor fraction of the excitatory input the majority originating in neighboring and recurrently connected cortical cells57 If the excitabiliry of cortical neurons is slightly higher than normal then this process of amplification may continue even after the LGN signals that initiated the reverberation are no longer being transmitted by the LGN ( a hysteretic mode of operation) 57

Feedback from hyperexcited cortical neurons will stream back to the LGN via corticogeniculate projections which outnumber geniculocortical projections ten-to-one One effect of this feedback is that the LGN is

able to absorb large amounts of information flowing back from the cortex 58

As signals reverberate back and forth in thalamocorticothalamic circuits a matching process takes place those geniculate relay cells that fire in patterns consistent with the firing patterns of active cortical cells will have their responshysivity enhanced while those geniculate cells that fire in patterns not consistent with cortical cells will be suppressed 59

Preservation of consciousness by selective facilitation of the visual pathways By combining all of the facilitatory effects produced by the authors eye movements and attentive fixation-(l) stimulation of the LGN by feedback from periorbital proprioception both directly and indirectly via the SC (2) the release of PGO waves (EMPs) that facilitate neurons in the LGN and primary visual cortex as they pass (3) the facilitation of the primary visual cortex by a state of relaxed immobile expectancy (4) attentive fixation and angle of gaze that facilitate PVNs in area PG (5) intracortical amplification of signals received from the LGN and (6) corticogeniculate feedback that stimulates the LGN-we delineate a circuit of enhanced excitability that extends from the LGN through the post-geniculate visual heirarchy to area PG where signals are integrated into representations of objects

The hyperexcitability of neurons all along the post-geniculate visual pathways creates conditions in the visual cortices which are similar to those present during EEG-desynchronized states of waking and REMS Therefore neurons in the visual pathways are too excitable to be entrained by synchronous bursting

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 140

patterns when spindle waves move through them instead the spindle bursts stimulate visual neurons to depolarize and then recover as happens in response to afferent sensory signals during waking states It is important to note that for this to occur none of the constituent neuron assemblies is required to perform an abnormal operation the abnormality is a function of the authors intent to activate contemporaneously neuron assemblies that would not normally be co-activated

PART IV HYPNOTIC ANALGESIA

Manipulation of spatial attention as a method for alleviating pain sensations In a theoretical article on the neurophysiology of hypnosis Crawford and Gruzelier60 propose that variations in hypnotizability are function of variability in the efficiency of the frontolimbic (anterior) attentional system in humans high-hypnotizables are better able to sustain focused attention on a task and to ignore extraneous stimuli than are low-hypnotizables

I na related empirical study that compares the use of attention by subjects with high versus low hypnotizability Crawford Brown and Moon61 report that highly hypnotizable persons continue to show physiological reactivity

while cognitively not perceiving the painful stimuli Through disattentional processes they can dissociate themselves from the awareness of pain The authors phosphene induction behaviors-and the cutaneous analgesia he experishyences-appear to involve the same kind of behaviors that is a mobilization of frontolimbic attention used to withdraw attention from external stimuli and to concentrate it on internally-generated phosphene images This suggests the hypothesis that the mechanisms that generate phosphenes might also produce hypnotic analgesia There are several ways that visual signals and pain signals might interact to produce this analgesia

Competition between pain and vision signals for limbic registration The fully-developed sensation of pain requires integration of rwo kinds of informashytion Signals that encode the location and intensity of a noxious stimulus (nociceptive signals) are relayed via the thalamus to the somatosensory cortices which registers only the sensory-discriminative aspects of pain perception62 before reaching consciousness the nociceptive signals must be sent to the limbic

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 141

system where they are linked with signals from long-term memory that encode the affective significance the stimulus has acquired for that individual Studies of brain metabolism show this linking of somatosensory information with limbic associations takes place in the anterior cingulate (CG) and anterior insula62-64

PET studies also show that the anterior CG is activated when subjects shift their spatial attention in response to expectations as to where

66stimuli will next appear65- This is precisely what takes place during the state of immobile expectancy that induces phosphenes Since visual signals and nociceptive signals both require limbic enhancement which is only possible if they get access to the anterior CG there might be conditions in which the two types of afferent sensory signals have to compete for that access In a theoretical article on the mechanisms of attention Posner and Rothbart67

propose that visual signals can interfere with nociceptive signals by blocking access to the anterior CG As behavioral evidence they cite studies showing that when young infants make distress calls they can be distracted by the presentation of a new visual stimulus We have shown the evidence of such control at about three months Orienting to visual events can be employed to quiet or calm negative vocalizations However the distress appears to be maintained and reappears when the infants attention to the stimulus is reduced Caregivers also report the use or visual orienting to block overt manifestations of distress at about this age 67

The effects of disattention on the somatosensory cortices If there is a competition between visual signals and nociceptive signals for access to the anterior CG it is likely that the competition will be affected by the relative volume of signals received A recent study suggests that focusing attention on internally-generated visual stimuli may reduce the number of nociceptive signals relayed by the somatosensory cortices Drevets Burton Videen Snyder Simpson and Raichle68 have shown that the mere anticipation of a touch at a specific cutaneous site increases the flow of blood to those cortical somatosenshysory neurons that are linked with that site where touch is expected and decreases the flow of blood to neurons linked with sites where touch is not expected In this experiment the researchers designated touch as the behaviorally significant sensory stimulus but their findings suggest that the outcome could be reversed if the instructions were reversed if subjects were

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page J42

instructed to direct attention away from a cutaneous site where a noxious stimulus was being applied if they were instructed to relax close their eyes and concentrate on the play of phosphenes in the visual field as the behaviorally significant sensory stimulus then it would be reasonable to expect that the flow of blood would decrease to the somatosensory neurons linked with the cutaneous stimulus and that the flow of blood would increase to the visual cortices The decrease in blood flow to somatosensory neurons implies less neuronal activity which implies that fewer signals are being sent forward to the anterior CG than would have been sent if instead the subject were treating the touch as the behaviorally significant sensory stimulus If fewer pain signals arrive at the anterior it is reasonable to infer that the conscious experience of pain will be muted by the diversion of attention to internal visual stimuli

Differential impact of sleep rhythms in the visual and nonvisual thalamus There is another mechanism that might also contribute to the analgesic effect of inducing sleep rhythms PET studies show that

the thalamus is involved in the relay of nociceptive signals to the cortex63 although some confusion remains about which kinds of signals are relayed by which subregions in the thalamus62 One thalamic site clearly identified by anatomical studies as a relay for nociceptive signals is the ventroposterior lateral nucleus (VPL)69 If synchronous sleep rhythms are active in the thalamus we can reasonably expect that the VPL will itself be entrained by synchronous oscillations and that it will relay the sleep rhythms to somatosensory cortices Relay neurons in the VPL are not stimulated by feedback from eye movements and fixation as are relay neurons in the LGN which suggests that sleep rhythms may impede the relay of nociceptive signals via the VPL but not the relay of visual signals via the LGN

Brain waves associated with anesthesia and NREMS The hypothesis presented here-that consciousness can be preserved despite the presence of NREMS activity-is consistent with a recent report that the kinds of fast brain waves which are normally associated with conscious states are also present during NREMS and anesthesia two states which were thought to involve minimal brain activityJo Another recent study found that there is a close resemblance between the slow brain waves that appear during NREMS and those that appear during certain types of anesthesia71

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 143

bull bull bull

CONCLUSION

In this paper we have presented evidence supporting the hypothesis that phosphene images can be generated as an epiphenomena of thalamic spindle bursts and delta wave activity normally associated with NREMS The prereqshyuisites for inducing these sleep rhythm phosphenes are relaxed immobile expectancy sustained convergence and attentive fixation of an undifferentiated visual field Our hypothesis provides a necessary and sufficient explanation for the authors induction of phosphenes and perhaps also for the generation of phosphenes reported to appear spontaneously during the drowsy transition to sleep (hypnagogic states) during sensory deprivation or during certain kinds of prayer or meditation all of which involve a similar state of relaxed immobile expectancyJ2

CORRESPONDENCE Philip T Nicholson bull 52 Norfolk Road bull Chestnut Hill MA 02167

REFERENCES amp NOTES

1 M 1 Posner Modulation by Instruction Nature 373 (1995) pp 198-199 2 J Reissenweber E David amp M pfotenhauer Investigations of Psychological Aspects of

the Perception of Magnetophosphenes and Electrophosphenes Biomedizinische Tecknik 373 (1992) pp 42-45

3 S M Kosslyn W L Thompson 1 J Kim amp N M Alpert Topographical Representations of Mental Images in Primary Visual Cortex Nature 378 (I995) pp 496-498

4 P E Roland amp B Gulyas Visual Memory Visual Imagery and Visual Recognition of Large Field Patterns by the Human Brain Functional Anatomy by Positron Emission Tomography Cerebral Cortex 51 (1995) pp 79-93

5 H Benson The Relaxation Response (Morrow New York NY 1975) 6 ] H Schultz amp W Luthe Autogenic Training a Physiological Approach to Psychotherapy

(Grune amp Stratton New York NY 1969) 7 E Jacobson Progressive Relaxation (University of Chicago Press Chicago IL 1938) 8 M A Steinmetz BC Motter C] DuffY amp V B Mountcastle Functional Properties

of Parietal Visual Neurons Radial Organization of Directionalities Within the Visual Field Journal ofNeuroscience 71 (1987) pp 177-191

9 R R Edelman Magnetic Resonance Imaging of the Nervous System Discussions in Neuroscience 71 Elsevier Science Amsterdam (I990) also J H Newhouse amp ] I Wiener Understanding MRI 1st Ed (Little Brown Boston MA 1991)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 144

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

CORTICAL PROCESSING OF CONTRADICTORY

WAVELENGTH SIGNALS

KEY _ Cells firing

cJ Cononol firing

Assume that as a spind6e wave moves through the LGNlt fires simultaneously aU the TC cells that represent a particular reUnoshytopic locus (x y) in each of the six laminae As a result cortical cells engaged In the higher level processing of visual signals will receive more wavelength signals representing retina locus (x y) than are generated by normal perception laquo and some of these afferent wavelength signals may contradict other signals arriving simultaneously

CORTICAL LIGHTNESS RECORD SlgnalSell

Intemal contradictions not congruent wilt pre

SmiddotON eristing neuron neta

s bullbull M-ON LmiddotON

3 bullbull M-OFF + L-OFF

a-ON 12

ROD-ON

No Internal eonlradlemiddot

--------1I =~8b~~~~~~~t signals

3+4

~ --OFF Excludes 6 Of 7 $J9n18

1+2 B-ON I

IWmiddotHmiddotI Signal Sell

1111111 No Intern1 conlrfldlcshy lion

Exelvdta 4 out of 7 efshy

bullbullbull bullbullbull ferant signals

No Intern1 contradic_ tionnee S-ON BshyOH and ROO-ON can all be coacllve at low lImlnance levels nef Ihe rod-eone break

ExchJde$ only 2 Ollt of 7 afferent signals

Figure 6 Selection of competing wavelength signals based on neuronal group selection This thought experiment is based on Edelman sconcept ofneuronal group selection 73 We assume that all possible combinations ofsignals will form sets and that all signal-sets will compete to make the most efficient match with pre-existing neuromd networks that have been forged over years ofnorma reti1U1-based perception We also assume that pre-existing neural networks are most likely to expedite those sets that satisfY 2 criteriI (J) the signals in a set do not contradict each other and (2) fower signals are excluded than in the other sets that satisfY the first criterion In our analysis Set 4 wins the competition because it does not contain internal contradictions and excludes fower signals (2 out of 7) than Set 3 excludes (4 out of7) It is not an internal contradiction that Set 4 contains both rods and cone Signtlls in normal retina-based perception when luminance levels approach the rod-cone break S-cone center-ON receptors send signas as do rod receptors and there is even evidence that rod activity may actually drive S-cone activity even after luminance levels foIl below the rod-cone break74 To calculate the cortical lightness record for Set 4 we average the wavelength that elicits maximal responses foom rods (511 nm) and for Sshycones (430 nm) which yields a mean wavelength of 470 nm which in humans results in a dark-blue or violet sensation

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 135

The cortical slow rhythm is an example of a generic pattern of neuronal excitashytion that occurs in large networks of neurons linked by local projections A recent experiment by Maeda Robinson and Kwana38 shows that networks of locally-connected neurons spontaneously generate periodic synchronized bursts of calcium transients that propagate across the network in an expanding spatial wave a pattern that represents a stable mode of firing towards which these neuronal networks relax following perturbations for example by electronic stimulation or by drugs Understanding the characteristics of these waves is an important prerequisite to understanding the mechanisms that produce the amorphous phosphene images as a visual epiphenomenon

To study the spontaneous periodic synchronized bursts the researchers prepared cultures of dissociated cortical neurons and allowed them to mature for several days in vitro (DIV) After 3 to 4 DIV when concenshy

trations of extracellular magnesium were low electrodes began to detect spontaneous synchronized bursts of low frequency calcium transients (between 01 and 1 Hz) that originated in different locations on the sheet every 10 to 20 seconds and spread across the sheet of cells at a relatively slow speed averaging 50 mmsecond The researchers could not predict where a wave would originate or where it would expand rather the initiation and expansion of waves was generated by spatial and temporal summation of a continuous random background of synaptic inputs including miniature spontaneous synaptic events but the pattern was not random since waves propagated sequentially from electrode to electrode as each local group of neurons charges up its neighboring nontefractory areas rather than in a random sequence of regions38

The excitability of the cells in the sheet determines the probability first that there will be a synchronous burst and second that it will spread in a particshyular direction Cells become more excitable as the cultures mature which means the refractory intervals between successive bursts were much shorter in mature cultures (gt 30 DIV) than in early cultures laquo 7 DIV) Some cells became so insensitive to inhibition that they continued to fire bursts even when extracellular concentrations of magnesium were relatively high Finally there were refractory periods of 5 to 10 seconds during which no bursts occurred even when an electrical stimulus was applied This refractory interval for cultured networks is slightly longer than the refractory interval observed of the cortical slow wave in vivo which 25 to 4 seconds 18- 19

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 136

Based on the observations about cortical slow waves we can predict that phosphenes generated as epiphenomena of delta wave activity will present the following signal characteristics (1) signals that appear at unpredictable locations in the VF (2) signals that expand and diverge asymmetrically following unpredictable trajectories which may encompass large areas of the VF (3) signals that move relatively slowly (50 mmsec) (4) signals that recur with a period of 2 to 4 seconds reflecting entrainment by the cortical slow wave (5) signals that do not terminate automatically after a predictable number of cycles

The spatial patterns of phosphene mists and thalamic delta waves are similar The spatiotemporal characteristics of amorphous phosphenes match the pattern of wave propagation associated with periodic spontashy

neous synchronized bursts in large neuron networks the amorphous phosphenes enter the visual field at unpredictable locations expand and diverge asymmetrically with a slow steady rate of flow follow trajectories that are unpredictable and exhibit a refractory interval The amorphous mists do appear to have a periodicity although the author is unable to sustain the vision while also counting the seconds therefore he is unable to determine if it compares to the period of the cortical slow wave (25 to 4 seconds) but his impression is that it feels roughly the same as as with receding annuli which recur at 5 seconds Also the refractory interval feels as if it decreases as the induction session is extended These similarities suggest that the amorphous phosphenes are generated by stage 2 NREMS delta wave activity which is an activity governed by the reverberation of the cortical slow wave in thalamoshycorticothalamic circuits The cortical slow wave is referred to the LGN where it modulates the firing of visual relay cells in the laminae and since relay cells do not have local dendritic connections the expansion of a wave of depolarshyizations moving from one relay cell to the next across in the laminar surface will mirror at least in part the expansion of the cortical wave that is spreading contemporaneously through locally-connected cortical cells

PART III RETENTION OF CONSCIOUSNESS

In a normal transition to NREMS the volley of synchronous spindle bursts that marks the onset of stage 2 NREMS overwhelms the normal firing pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 137

of thalamocortical cells preventing their relay of afferent sensory signals and inducing a loss of consciousness21 But the loss of consciousness cannot be timed precisely using cortical EEG the thalamus is too remote for the onset of spindling to be reliably detected by scalp electrodes39 In experiments with cats where electrodes could be implanted in the thalamus researchers found that spindling often reached peak levels of activity in the thalamus-a level of activity consonant with stage 2 NREMS-at a time when the cortical EEG was still showing intermittent desynchronizations a pattern characteristic of the drowsy stage 1 transition not a fully-established stage 2 NREMS episode4o

In other words there is a short period of time in which the synchronous rhythms of stage 2 NREMS are installed in the thalamus but not in the cortex where cortical neurons continue to depolarize in response to afferent sensory signals

T his finding suggests a possible explanation for the authors ability to retain consciousness while spindle bursts are sweeping through the LGN if he is able to extend the duration of this time lag between

the onset of spindling in the thalamus and spindling in the cortex if he is able to stimulate the visual cortices in such a way that they continue to depolarize then he may be able to keep on processing visual signals-to remain visually aware-even after the non-visual thalamus and non-visual cortex become entrained by synchronous sleep rhythms The authors induction technique includes several behaviors which are known to enhance the responsiveness of visual neurons-eye movements attentive fixation and an attitude of expectancy

Effects of eye movements and attention on the LGN Sustained convergence causes periorbital proprioceptors to send excitatory feedback directly to the LGN41 Also convergence further enhances the excitability of geniculate cells by stimulating the superior collicus (SC) which sends its own excitatory signals to the LGN42-43 These signals from the SC are known to selectively enhance the excitability of visual relay cells that represent the periphery of vision44 We know in the authors case that the SC is being stimulated because he is able to keep on fixating an ability which would normally be lost during the transishytion to NREMS45 The ability to fixate can be retained however if the SC is stimulated (even if stimulated during NREMS)46

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 138

Effects of eye movement attention and expectancy on the primary visual cortex The PET study of mental imagery by Kosslyn et al 3 showed that even a baseline resting state of relaxed immobile expectancy can generate signifishycant increases in neuronal activity in the primary visual cortices Further increases can be induced by sustained eye movements

A sustained convergence will release a stream of ponto-geniculo-occipital (PGO) waves These PGO waves called eye movement potentials or EMPs last only as long as the eye movement1747 whereas the PGO waves associated with rapid-eye-movement sleep (REMS) fire continually for the duration of the REMS episode Both REMS-related PGO waves and EMPs have the same desynchronizing effect on the visual pathways they move through the LGN depolarizing the thalamocortical cells which relay the signals to cortical neurons The responsivity of neurons in the primary visual cortices is enhanced by the stimulation of PGO waves 1747-49 If the passage of EMPs causes the genicushylate relay cells and their cortical targets to depolarize regularly then a volley of 4 spindle bursts moving through the same pathways will register as just another series of depolarizations in effect the spindle bursts are processed by the visual system as if they were sensory signals sent from the retina rather than an event stimulated by endogenous mechanisms

T he impact of eye movements and ftxation on the parietal visual cortex Convergence and attentive fixation will also enhance the responsiveness of light-sensitive parietal visual neurons (PVNs) in area PG of the

posterior parietal cortex 50 In experiments where monkeys are trained to fix their attention on a screen-and to keep on fixating even if no targets appearshythe excitability of these light-sensitive PVNs increases by as much as 350 51

52-53Responsiveness is also facilitated by the angle of gaze Also area PG is the first region in the visual pathways containing individual neurons with the capacity to respond to large bilateral stimuli moving in opposite directions along the central meridians of vision (opponent vector motion) 853-55 Facilitation of PVNs in area PG has the effect of sensitizing the subject to bilateral opponent vector motion and this is especially true if the movement appears in the periphery of the VE 8

Intracortical ampliftcation and feedback to the LGN When PGO waves and signals from the SC arrive in the primary visual cortex they may be relatively weak however weak signals can be amplified by reverberating in large networks

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 139

of cortical cells linked by local projection 56 There are nine times as many excitatory links among cortical cells as there are projections from the visual cortex to the LGN an imbalance which suggests leads Suarez Koch and Douglas to propose that geniculate input provides only a minor fraction of the excitatory input the majority originating in neighboring and recurrently connected cortical cells57 If the excitabiliry of cortical neurons is slightly higher than normal then this process of amplification may continue even after the LGN signals that initiated the reverberation are no longer being transmitted by the LGN ( a hysteretic mode of operation) 57

Feedback from hyperexcited cortical neurons will stream back to the LGN via corticogeniculate projections which outnumber geniculocortical projections ten-to-one One effect of this feedback is that the LGN is

able to absorb large amounts of information flowing back from the cortex 58

As signals reverberate back and forth in thalamocorticothalamic circuits a matching process takes place those geniculate relay cells that fire in patterns consistent with the firing patterns of active cortical cells will have their responshysivity enhanced while those geniculate cells that fire in patterns not consistent with cortical cells will be suppressed 59

Preservation of consciousness by selective facilitation of the visual pathways By combining all of the facilitatory effects produced by the authors eye movements and attentive fixation-(l) stimulation of the LGN by feedback from periorbital proprioception both directly and indirectly via the SC (2) the release of PGO waves (EMPs) that facilitate neurons in the LGN and primary visual cortex as they pass (3) the facilitation of the primary visual cortex by a state of relaxed immobile expectancy (4) attentive fixation and angle of gaze that facilitate PVNs in area PG (5) intracortical amplification of signals received from the LGN and (6) corticogeniculate feedback that stimulates the LGN-we delineate a circuit of enhanced excitability that extends from the LGN through the post-geniculate visual heirarchy to area PG where signals are integrated into representations of objects

The hyperexcitability of neurons all along the post-geniculate visual pathways creates conditions in the visual cortices which are similar to those present during EEG-desynchronized states of waking and REMS Therefore neurons in the visual pathways are too excitable to be entrained by synchronous bursting

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 140

patterns when spindle waves move through them instead the spindle bursts stimulate visual neurons to depolarize and then recover as happens in response to afferent sensory signals during waking states It is important to note that for this to occur none of the constituent neuron assemblies is required to perform an abnormal operation the abnormality is a function of the authors intent to activate contemporaneously neuron assemblies that would not normally be co-activated

PART IV HYPNOTIC ANALGESIA

Manipulation of spatial attention as a method for alleviating pain sensations In a theoretical article on the neurophysiology of hypnosis Crawford and Gruzelier60 propose that variations in hypnotizability are function of variability in the efficiency of the frontolimbic (anterior) attentional system in humans high-hypnotizables are better able to sustain focused attention on a task and to ignore extraneous stimuli than are low-hypnotizables

I na related empirical study that compares the use of attention by subjects with high versus low hypnotizability Crawford Brown and Moon61 report that highly hypnotizable persons continue to show physiological reactivity

while cognitively not perceiving the painful stimuli Through disattentional processes they can dissociate themselves from the awareness of pain The authors phosphene induction behaviors-and the cutaneous analgesia he experishyences-appear to involve the same kind of behaviors that is a mobilization of frontolimbic attention used to withdraw attention from external stimuli and to concentrate it on internally-generated phosphene images This suggests the hypothesis that the mechanisms that generate phosphenes might also produce hypnotic analgesia There are several ways that visual signals and pain signals might interact to produce this analgesia

Competition between pain and vision signals for limbic registration The fully-developed sensation of pain requires integration of rwo kinds of informashytion Signals that encode the location and intensity of a noxious stimulus (nociceptive signals) are relayed via the thalamus to the somatosensory cortices which registers only the sensory-discriminative aspects of pain perception62 before reaching consciousness the nociceptive signals must be sent to the limbic

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 141

system where they are linked with signals from long-term memory that encode the affective significance the stimulus has acquired for that individual Studies of brain metabolism show this linking of somatosensory information with limbic associations takes place in the anterior cingulate (CG) and anterior insula62-64

PET studies also show that the anterior CG is activated when subjects shift their spatial attention in response to expectations as to where

66stimuli will next appear65- This is precisely what takes place during the state of immobile expectancy that induces phosphenes Since visual signals and nociceptive signals both require limbic enhancement which is only possible if they get access to the anterior CG there might be conditions in which the two types of afferent sensory signals have to compete for that access In a theoretical article on the mechanisms of attention Posner and Rothbart67

propose that visual signals can interfere with nociceptive signals by blocking access to the anterior CG As behavioral evidence they cite studies showing that when young infants make distress calls they can be distracted by the presentation of a new visual stimulus We have shown the evidence of such control at about three months Orienting to visual events can be employed to quiet or calm negative vocalizations However the distress appears to be maintained and reappears when the infants attention to the stimulus is reduced Caregivers also report the use or visual orienting to block overt manifestations of distress at about this age 67

The effects of disattention on the somatosensory cortices If there is a competition between visual signals and nociceptive signals for access to the anterior CG it is likely that the competition will be affected by the relative volume of signals received A recent study suggests that focusing attention on internally-generated visual stimuli may reduce the number of nociceptive signals relayed by the somatosensory cortices Drevets Burton Videen Snyder Simpson and Raichle68 have shown that the mere anticipation of a touch at a specific cutaneous site increases the flow of blood to those cortical somatosenshysory neurons that are linked with that site where touch is expected and decreases the flow of blood to neurons linked with sites where touch is not expected In this experiment the researchers designated touch as the behaviorally significant sensory stimulus but their findings suggest that the outcome could be reversed if the instructions were reversed if subjects were

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page J42

instructed to direct attention away from a cutaneous site where a noxious stimulus was being applied if they were instructed to relax close their eyes and concentrate on the play of phosphenes in the visual field as the behaviorally significant sensory stimulus then it would be reasonable to expect that the flow of blood would decrease to the somatosensory neurons linked with the cutaneous stimulus and that the flow of blood would increase to the visual cortices The decrease in blood flow to somatosensory neurons implies less neuronal activity which implies that fewer signals are being sent forward to the anterior CG than would have been sent if instead the subject were treating the touch as the behaviorally significant sensory stimulus If fewer pain signals arrive at the anterior it is reasonable to infer that the conscious experience of pain will be muted by the diversion of attention to internal visual stimuli

Differential impact of sleep rhythms in the visual and nonvisual thalamus There is another mechanism that might also contribute to the analgesic effect of inducing sleep rhythms PET studies show that

the thalamus is involved in the relay of nociceptive signals to the cortex63 although some confusion remains about which kinds of signals are relayed by which subregions in the thalamus62 One thalamic site clearly identified by anatomical studies as a relay for nociceptive signals is the ventroposterior lateral nucleus (VPL)69 If synchronous sleep rhythms are active in the thalamus we can reasonably expect that the VPL will itself be entrained by synchronous oscillations and that it will relay the sleep rhythms to somatosensory cortices Relay neurons in the VPL are not stimulated by feedback from eye movements and fixation as are relay neurons in the LGN which suggests that sleep rhythms may impede the relay of nociceptive signals via the VPL but not the relay of visual signals via the LGN

Brain waves associated with anesthesia and NREMS The hypothesis presented here-that consciousness can be preserved despite the presence of NREMS activity-is consistent with a recent report that the kinds of fast brain waves which are normally associated with conscious states are also present during NREMS and anesthesia two states which were thought to involve minimal brain activityJo Another recent study found that there is a close resemblance between the slow brain waves that appear during NREMS and those that appear during certain types of anesthesia71

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 143

bull bull bull

CONCLUSION

In this paper we have presented evidence supporting the hypothesis that phosphene images can be generated as an epiphenomena of thalamic spindle bursts and delta wave activity normally associated with NREMS The prereqshyuisites for inducing these sleep rhythm phosphenes are relaxed immobile expectancy sustained convergence and attentive fixation of an undifferentiated visual field Our hypothesis provides a necessary and sufficient explanation for the authors induction of phosphenes and perhaps also for the generation of phosphenes reported to appear spontaneously during the drowsy transition to sleep (hypnagogic states) during sensory deprivation or during certain kinds of prayer or meditation all of which involve a similar state of relaxed immobile expectancyJ2

CORRESPONDENCE Philip T Nicholson bull 52 Norfolk Road bull Chestnut Hill MA 02167

REFERENCES amp NOTES

1 M 1 Posner Modulation by Instruction Nature 373 (1995) pp 198-199 2 J Reissenweber E David amp M pfotenhauer Investigations of Psychological Aspects of

the Perception of Magnetophosphenes and Electrophosphenes Biomedizinische Tecknik 373 (1992) pp 42-45

3 S M Kosslyn W L Thompson 1 J Kim amp N M Alpert Topographical Representations of Mental Images in Primary Visual Cortex Nature 378 (I995) pp 496-498

4 P E Roland amp B Gulyas Visual Memory Visual Imagery and Visual Recognition of Large Field Patterns by the Human Brain Functional Anatomy by Positron Emission Tomography Cerebral Cortex 51 (1995) pp 79-93

5 H Benson The Relaxation Response (Morrow New York NY 1975) 6 ] H Schultz amp W Luthe Autogenic Training a Physiological Approach to Psychotherapy

(Grune amp Stratton New York NY 1969) 7 E Jacobson Progressive Relaxation (University of Chicago Press Chicago IL 1938) 8 M A Steinmetz BC Motter C] DuffY amp V B Mountcastle Functional Properties

of Parietal Visual Neurons Radial Organization of Directionalities Within the Visual Field Journal ofNeuroscience 71 (1987) pp 177-191

9 R R Edelman Magnetic Resonance Imaging of the Nervous System Discussions in Neuroscience 71 Elsevier Science Amsterdam (I990) also J H Newhouse amp ] I Wiener Understanding MRI 1st Ed (Little Brown Boston MA 1991)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 144

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

The cortical slow rhythm is an example of a generic pattern of neuronal excitashytion that occurs in large networks of neurons linked by local projections A recent experiment by Maeda Robinson and Kwana38 shows that networks of locally-connected neurons spontaneously generate periodic synchronized bursts of calcium transients that propagate across the network in an expanding spatial wave a pattern that represents a stable mode of firing towards which these neuronal networks relax following perturbations for example by electronic stimulation or by drugs Understanding the characteristics of these waves is an important prerequisite to understanding the mechanisms that produce the amorphous phosphene images as a visual epiphenomenon

To study the spontaneous periodic synchronized bursts the researchers prepared cultures of dissociated cortical neurons and allowed them to mature for several days in vitro (DIV) After 3 to 4 DIV when concenshy

trations of extracellular magnesium were low electrodes began to detect spontaneous synchronized bursts of low frequency calcium transients (between 01 and 1 Hz) that originated in different locations on the sheet every 10 to 20 seconds and spread across the sheet of cells at a relatively slow speed averaging 50 mmsecond The researchers could not predict where a wave would originate or where it would expand rather the initiation and expansion of waves was generated by spatial and temporal summation of a continuous random background of synaptic inputs including miniature spontaneous synaptic events but the pattern was not random since waves propagated sequentially from electrode to electrode as each local group of neurons charges up its neighboring nontefractory areas rather than in a random sequence of regions38

The excitability of the cells in the sheet determines the probability first that there will be a synchronous burst and second that it will spread in a particshyular direction Cells become more excitable as the cultures mature which means the refractory intervals between successive bursts were much shorter in mature cultures (gt 30 DIV) than in early cultures laquo 7 DIV) Some cells became so insensitive to inhibition that they continued to fire bursts even when extracellular concentrations of magnesium were relatively high Finally there were refractory periods of 5 to 10 seconds during which no bursts occurred even when an electrical stimulus was applied This refractory interval for cultured networks is slightly longer than the refractory interval observed of the cortical slow wave in vivo which 25 to 4 seconds 18- 19

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 136

Based on the observations about cortical slow waves we can predict that phosphenes generated as epiphenomena of delta wave activity will present the following signal characteristics (1) signals that appear at unpredictable locations in the VF (2) signals that expand and diverge asymmetrically following unpredictable trajectories which may encompass large areas of the VF (3) signals that move relatively slowly (50 mmsec) (4) signals that recur with a period of 2 to 4 seconds reflecting entrainment by the cortical slow wave (5) signals that do not terminate automatically after a predictable number of cycles

The spatial patterns of phosphene mists and thalamic delta waves are similar The spatiotemporal characteristics of amorphous phosphenes match the pattern of wave propagation associated with periodic spontashy

neous synchronized bursts in large neuron networks the amorphous phosphenes enter the visual field at unpredictable locations expand and diverge asymmetrically with a slow steady rate of flow follow trajectories that are unpredictable and exhibit a refractory interval The amorphous mists do appear to have a periodicity although the author is unable to sustain the vision while also counting the seconds therefore he is unable to determine if it compares to the period of the cortical slow wave (25 to 4 seconds) but his impression is that it feels roughly the same as as with receding annuli which recur at 5 seconds Also the refractory interval feels as if it decreases as the induction session is extended These similarities suggest that the amorphous phosphenes are generated by stage 2 NREMS delta wave activity which is an activity governed by the reverberation of the cortical slow wave in thalamoshycorticothalamic circuits The cortical slow wave is referred to the LGN where it modulates the firing of visual relay cells in the laminae and since relay cells do not have local dendritic connections the expansion of a wave of depolarshyizations moving from one relay cell to the next across in the laminar surface will mirror at least in part the expansion of the cortical wave that is spreading contemporaneously through locally-connected cortical cells

PART III RETENTION OF CONSCIOUSNESS

In a normal transition to NREMS the volley of synchronous spindle bursts that marks the onset of stage 2 NREMS overwhelms the normal firing pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 137

of thalamocortical cells preventing their relay of afferent sensory signals and inducing a loss of consciousness21 But the loss of consciousness cannot be timed precisely using cortical EEG the thalamus is too remote for the onset of spindling to be reliably detected by scalp electrodes39 In experiments with cats where electrodes could be implanted in the thalamus researchers found that spindling often reached peak levels of activity in the thalamus-a level of activity consonant with stage 2 NREMS-at a time when the cortical EEG was still showing intermittent desynchronizations a pattern characteristic of the drowsy stage 1 transition not a fully-established stage 2 NREMS episode4o

In other words there is a short period of time in which the synchronous rhythms of stage 2 NREMS are installed in the thalamus but not in the cortex where cortical neurons continue to depolarize in response to afferent sensory signals

T his finding suggests a possible explanation for the authors ability to retain consciousness while spindle bursts are sweeping through the LGN if he is able to extend the duration of this time lag between

the onset of spindling in the thalamus and spindling in the cortex if he is able to stimulate the visual cortices in such a way that they continue to depolarize then he may be able to keep on processing visual signals-to remain visually aware-even after the non-visual thalamus and non-visual cortex become entrained by synchronous sleep rhythms The authors induction technique includes several behaviors which are known to enhance the responsiveness of visual neurons-eye movements attentive fixation and an attitude of expectancy

Effects of eye movements and attention on the LGN Sustained convergence causes periorbital proprioceptors to send excitatory feedback directly to the LGN41 Also convergence further enhances the excitability of geniculate cells by stimulating the superior collicus (SC) which sends its own excitatory signals to the LGN42-43 These signals from the SC are known to selectively enhance the excitability of visual relay cells that represent the periphery of vision44 We know in the authors case that the SC is being stimulated because he is able to keep on fixating an ability which would normally be lost during the transishytion to NREMS45 The ability to fixate can be retained however if the SC is stimulated (even if stimulated during NREMS)46

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 138

Effects of eye movement attention and expectancy on the primary visual cortex The PET study of mental imagery by Kosslyn et al 3 showed that even a baseline resting state of relaxed immobile expectancy can generate signifishycant increases in neuronal activity in the primary visual cortices Further increases can be induced by sustained eye movements

A sustained convergence will release a stream of ponto-geniculo-occipital (PGO) waves These PGO waves called eye movement potentials or EMPs last only as long as the eye movement1747 whereas the PGO waves associated with rapid-eye-movement sleep (REMS) fire continually for the duration of the REMS episode Both REMS-related PGO waves and EMPs have the same desynchronizing effect on the visual pathways they move through the LGN depolarizing the thalamocortical cells which relay the signals to cortical neurons The responsivity of neurons in the primary visual cortices is enhanced by the stimulation of PGO waves 1747-49 If the passage of EMPs causes the genicushylate relay cells and their cortical targets to depolarize regularly then a volley of 4 spindle bursts moving through the same pathways will register as just another series of depolarizations in effect the spindle bursts are processed by the visual system as if they were sensory signals sent from the retina rather than an event stimulated by endogenous mechanisms

T he impact of eye movements and ftxation on the parietal visual cortex Convergence and attentive fixation will also enhance the responsiveness of light-sensitive parietal visual neurons (PVNs) in area PG of the

posterior parietal cortex 50 In experiments where monkeys are trained to fix their attention on a screen-and to keep on fixating even if no targets appearshythe excitability of these light-sensitive PVNs increases by as much as 350 51

52-53Responsiveness is also facilitated by the angle of gaze Also area PG is the first region in the visual pathways containing individual neurons with the capacity to respond to large bilateral stimuli moving in opposite directions along the central meridians of vision (opponent vector motion) 853-55 Facilitation of PVNs in area PG has the effect of sensitizing the subject to bilateral opponent vector motion and this is especially true if the movement appears in the periphery of the VE 8

Intracortical ampliftcation and feedback to the LGN When PGO waves and signals from the SC arrive in the primary visual cortex they may be relatively weak however weak signals can be amplified by reverberating in large networks

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 139

of cortical cells linked by local projection 56 There are nine times as many excitatory links among cortical cells as there are projections from the visual cortex to the LGN an imbalance which suggests leads Suarez Koch and Douglas to propose that geniculate input provides only a minor fraction of the excitatory input the majority originating in neighboring and recurrently connected cortical cells57 If the excitabiliry of cortical neurons is slightly higher than normal then this process of amplification may continue even after the LGN signals that initiated the reverberation are no longer being transmitted by the LGN ( a hysteretic mode of operation) 57

Feedback from hyperexcited cortical neurons will stream back to the LGN via corticogeniculate projections which outnumber geniculocortical projections ten-to-one One effect of this feedback is that the LGN is

able to absorb large amounts of information flowing back from the cortex 58

As signals reverberate back and forth in thalamocorticothalamic circuits a matching process takes place those geniculate relay cells that fire in patterns consistent with the firing patterns of active cortical cells will have their responshysivity enhanced while those geniculate cells that fire in patterns not consistent with cortical cells will be suppressed 59

Preservation of consciousness by selective facilitation of the visual pathways By combining all of the facilitatory effects produced by the authors eye movements and attentive fixation-(l) stimulation of the LGN by feedback from periorbital proprioception both directly and indirectly via the SC (2) the release of PGO waves (EMPs) that facilitate neurons in the LGN and primary visual cortex as they pass (3) the facilitation of the primary visual cortex by a state of relaxed immobile expectancy (4) attentive fixation and angle of gaze that facilitate PVNs in area PG (5) intracortical amplification of signals received from the LGN and (6) corticogeniculate feedback that stimulates the LGN-we delineate a circuit of enhanced excitability that extends from the LGN through the post-geniculate visual heirarchy to area PG where signals are integrated into representations of objects

The hyperexcitability of neurons all along the post-geniculate visual pathways creates conditions in the visual cortices which are similar to those present during EEG-desynchronized states of waking and REMS Therefore neurons in the visual pathways are too excitable to be entrained by synchronous bursting

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 140

patterns when spindle waves move through them instead the spindle bursts stimulate visual neurons to depolarize and then recover as happens in response to afferent sensory signals during waking states It is important to note that for this to occur none of the constituent neuron assemblies is required to perform an abnormal operation the abnormality is a function of the authors intent to activate contemporaneously neuron assemblies that would not normally be co-activated

PART IV HYPNOTIC ANALGESIA

Manipulation of spatial attention as a method for alleviating pain sensations In a theoretical article on the neurophysiology of hypnosis Crawford and Gruzelier60 propose that variations in hypnotizability are function of variability in the efficiency of the frontolimbic (anterior) attentional system in humans high-hypnotizables are better able to sustain focused attention on a task and to ignore extraneous stimuli than are low-hypnotizables

I na related empirical study that compares the use of attention by subjects with high versus low hypnotizability Crawford Brown and Moon61 report that highly hypnotizable persons continue to show physiological reactivity

while cognitively not perceiving the painful stimuli Through disattentional processes they can dissociate themselves from the awareness of pain The authors phosphene induction behaviors-and the cutaneous analgesia he experishyences-appear to involve the same kind of behaviors that is a mobilization of frontolimbic attention used to withdraw attention from external stimuli and to concentrate it on internally-generated phosphene images This suggests the hypothesis that the mechanisms that generate phosphenes might also produce hypnotic analgesia There are several ways that visual signals and pain signals might interact to produce this analgesia

Competition between pain and vision signals for limbic registration The fully-developed sensation of pain requires integration of rwo kinds of informashytion Signals that encode the location and intensity of a noxious stimulus (nociceptive signals) are relayed via the thalamus to the somatosensory cortices which registers only the sensory-discriminative aspects of pain perception62 before reaching consciousness the nociceptive signals must be sent to the limbic

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 141

system where they are linked with signals from long-term memory that encode the affective significance the stimulus has acquired for that individual Studies of brain metabolism show this linking of somatosensory information with limbic associations takes place in the anterior cingulate (CG) and anterior insula62-64

PET studies also show that the anterior CG is activated when subjects shift their spatial attention in response to expectations as to where

66stimuli will next appear65- This is precisely what takes place during the state of immobile expectancy that induces phosphenes Since visual signals and nociceptive signals both require limbic enhancement which is only possible if they get access to the anterior CG there might be conditions in which the two types of afferent sensory signals have to compete for that access In a theoretical article on the mechanisms of attention Posner and Rothbart67

propose that visual signals can interfere with nociceptive signals by blocking access to the anterior CG As behavioral evidence they cite studies showing that when young infants make distress calls they can be distracted by the presentation of a new visual stimulus We have shown the evidence of such control at about three months Orienting to visual events can be employed to quiet or calm negative vocalizations However the distress appears to be maintained and reappears when the infants attention to the stimulus is reduced Caregivers also report the use or visual orienting to block overt manifestations of distress at about this age 67

The effects of disattention on the somatosensory cortices If there is a competition between visual signals and nociceptive signals for access to the anterior CG it is likely that the competition will be affected by the relative volume of signals received A recent study suggests that focusing attention on internally-generated visual stimuli may reduce the number of nociceptive signals relayed by the somatosensory cortices Drevets Burton Videen Snyder Simpson and Raichle68 have shown that the mere anticipation of a touch at a specific cutaneous site increases the flow of blood to those cortical somatosenshysory neurons that are linked with that site where touch is expected and decreases the flow of blood to neurons linked with sites where touch is not expected In this experiment the researchers designated touch as the behaviorally significant sensory stimulus but their findings suggest that the outcome could be reversed if the instructions were reversed if subjects were

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page J42

instructed to direct attention away from a cutaneous site where a noxious stimulus was being applied if they were instructed to relax close their eyes and concentrate on the play of phosphenes in the visual field as the behaviorally significant sensory stimulus then it would be reasonable to expect that the flow of blood would decrease to the somatosensory neurons linked with the cutaneous stimulus and that the flow of blood would increase to the visual cortices The decrease in blood flow to somatosensory neurons implies less neuronal activity which implies that fewer signals are being sent forward to the anterior CG than would have been sent if instead the subject were treating the touch as the behaviorally significant sensory stimulus If fewer pain signals arrive at the anterior it is reasonable to infer that the conscious experience of pain will be muted by the diversion of attention to internal visual stimuli

Differential impact of sleep rhythms in the visual and nonvisual thalamus There is another mechanism that might also contribute to the analgesic effect of inducing sleep rhythms PET studies show that

the thalamus is involved in the relay of nociceptive signals to the cortex63 although some confusion remains about which kinds of signals are relayed by which subregions in the thalamus62 One thalamic site clearly identified by anatomical studies as a relay for nociceptive signals is the ventroposterior lateral nucleus (VPL)69 If synchronous sleep rhythms are active in the thalamus we can reasonably expect that the VPL will itself be entrained by synchronous oscillations and that it will relay the sleep rhythms to somatosensory cortices Relay neurons in the VPL are not stimulated by feedback from eye movements and fixation as are relay neurons in the LGN which suggests that sleep rhythms may impede the relay of nociceptive signals via the VPL but not the relay of visual signals via the LGN

Brain waves associated with anesthesia and NREMS The hypothesis presented here-that consciousness can be preserved despite the presence of NREMS activity-is consistent with a recent report that the kinds of fast brain waves which are normally associated with conscious states are also present during NREMS and anesthesia two states which were thought to involve minimal brain activityJo Another recent study found that there is a close resemblance between the slow brain waves that appear during NREMS and those that appear during certain types of anesthesia71

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 143

bull bull bull

CONCLUSION

In this paper we have presented evidence supporting the hypothesis that phosphene images can be generated as an epiphenomena of thalamic spindle bursts and delta wave activity normally associated with NREMS The prereqshyuisites for inducing these sleep rhythm phosphenes are relaxed immobile expectancy sustained convergence and attentive fixation of an undifferentiated visual field Our hypothesis provides a necessary and sufficient explanation for the authors induction of phosphenes and perhaps also for the generation of phosphenes reported to appear spontaneously during the drowsy transition to sleep (hypnagogic states) during sensory deprivation or during certain kinds of prayer or meditation all of which involve a similar state of relaxed immobile expectancyJ2

CORRESPONDENCE Philip T Nicholson bull 52 Norfolk Road bull Chestnut Hill MA 02167

REFERENCES amp NOTES

1 M 1 Posner Modulation by Instruction Nature 373 (1995) pp 198-199 2 J Reissenweber E David amp M pfotenhauer Investigations of Psychological Aspects of

the Perception of Magnetophosphenes and Electrophosphenes Biomedizinische Tecknik 373 (1992) pp 42-45

3 S M Kosslyn W L Thompson 1 J Kim amp N M Alpert Topographical Representations of Mental Images in Primary Visual Cortex Nature 378 (I995) pp 496-498

4 P E Roland amp B Gulyas Visual Memory Visual Imagery and Visual Recognition of Large Field Patterns by the Human Brain Functional Anatomy by Positron Emission Tomography Cerebral Cortex 51 (1995) pp 79-93

5 H Benson The Relaxation Response (Morrow New York NY 1975) 6 ] H Schultz amp W Luthe Autogenic Training a Physiological Approach to Psychotherapy

(Grune amp Stratton New York NY 1969) 7 E Jacobson Progressive Relaxation (University of Chicago Press Chicago IL 1938) 8 M A Steinmetz BC Motter C] DuffY amp V B Mountcastle Functional Properties

of Parietal Visual Neurons Radial Organization of Directionalities Within the Visual Field Journal ofNeuroscience 71 (1987) pp 177-191

9 R R Edelman Magnetic Resonance Imaging of the Nervous System Discussions in Neuroscience 71 Elsevier Science Amsterdam (I990) also J H Newhouse amp ] I Wiener Understanding MRI 1st Ed (Little Brown Boston MA 1991)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 144

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

Based on the observations about cortical slow waves we can predict that phosphenes generated as epiphenomena of delta wave activity will present the following signal characteristics (1) signals that appear at unpredictable locations in the VF (2) signals that expand and diverge asymmetrically following unpredictable trajectories which may encompass large areas of the VF (3) signals that move relatively slowly (50 mmsec) (4) signals that recur with a period of 2 to 4 seconds reflecting entrainment by the cortical slow wave (5) signals that do not terminate automatically after a predictable number of cycles

The spatial patterns of phosphene mists and thalamic delta waves are similar The spatiotemporal characteristics of amorphous phosphenes match the pattern of wave propagation associated with periodic spontashy

neous synchronized bursts in large neuron networks the amorphous phosphenes enter the visual field at unpredictable locations expand and diverge asymmetrically with a slow steady rate of flow follow trajectories that are unpredictable and exhibit a refractory interval The amorphous mists do appear to have a periodicity although the author is unable to sustain the vision while also counting the seconds therefore he is unable to determine if it compares to the period of the cortical slow wave (25 to 4 seconds) but his impression is that it feels roughly the same as as with receding annuli which recur at 5 seconds Also the refractory interval feels as if it decreases as the induction session is extended These similarities suggest that the amorphous phosphenes are generated by stage 2 NREMS delta wave activity which is an activity governed by the reverberation of the cortical slow wave in thalamoshycorticothalamic circuits The cortical slow wave is referred to the LGN where it modulates the firing of visual relay cells in the laminae and since relay cells do not have local dendritic connections the expansion of a wave of depolarshyizations moving from one relay cell to the next across in the laminar surface will mirror at least in part the expansion of the cortical wave that is spreading contemporaneously through locally-connected cortical cells

PART III RETENTION OF CONSCIOUSNESS

In a normal transition to NREMS the volley of synchronous spindle bursts that marks the onset of stage 2 NREMS overwhelms the normal firing pattern

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 137

of thalamocortical cells preventing their relay of afferent sensory signals and inducing a loss of consciousness21 But the loss of consciousness cannot be timed precisely using cortical EEG the thalamus is too remote for the onset of spindling to be reliably detected by scalp electrodes39 In experiments with cats where electrodes could be implanted in the thalamus researchers found that spindling often reached peak levels of activity in the thalamus-a level of activity consonant with stage 2 NREMS-at a time when the cortical EEG was still showing intermittent desynchronizations a pattern characteristic of the drowsy stage 1 transition not a fully-established stage 2 NREMS episode4o

In other words there is a short period of time in which the synchronous rhythms of stage 2 NREMS are installed in the thalamus but not in the cortex where cortical neurons continue to depolarize in response to afferent sensory signals

T his finding suggests a possible explanation for the authors ability to retain consciousness while spindle bursts are sweeping through the LGN if he is able to extend the duration of this time lag between

the onset of spindling in the thalamus and spindling in the cortex if he is able to stimulate the visual cortices in such a way that they continue to depolarize then he may be able to keep on processing visual signals-to remain visually aware-even after the non-visual thalamus and non-visual cortex become entrained by synchronous sleep rhythms The authors induction technique includes several behaviors which are known to enhance the responsiveness of visual neurons-eye movements attentive fixation and an attitude of expectancy

Effects of eye movements and attention on the LGN Sustained convergence causes periorbital proprioceptors to send excitatory feedback directly to the LGN41 Also convergence further enhances the excitability of geniculate cells by stimulating the superior collicus (SC) which sends its own excitatory signals to the LGN42-43 These signals from the SC are known to selectively enhance the excitability of visual relay cells that represent the periphery of vision44 We know in the authors case that the SC is being stimulated because he is able to keep on fixating an ability which would normally be lost during the transishytion to NREMS45 The ability to fixate can be retained however if the SC is stimulated (even if stimulated during NREMS)46

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 138

Effects of eye movement attention and expectancy on the primary visual cortex The PET study of mental imagery by Kosslyn et al 3 showed that even a baseline resting state of relaxed immobile expectancy can generate signifishycant increases in neuronal activity in the primary visual cortices Further increases can be induced by sustained eye movements

A sustained convergence will release a stream of ponto-geniculo-occipital (PGO) waves These PGO waves called eye movement potentials or EMPs last only as long as the eye movement1747 whereas the PGO waves associated with rapid-eye-movement sleep (REMS) fire continually for the duration of the REMS episode Both REMS-related PGO waves and EMPs have the same desynchronizing effect on the visual pathways they move through the LGN depolarizing the thalamocortical cells which relay the signals to cortical neurons The responsivity of neurons in the primary visual cortices is enhanced by the stimulation of PGO waves 1747-49 If the passage of EMPs causes the genicushylate relay cells and their cortical targets to depolarize regularly then a volley of 4 spindle bursts moving through the same pathways will register as just another series of depolarizations in effect the spindle bursts are processed by the visual system as if they were sensory signals sent from the retina rather than an event stimulated by endogenous mechanisms

T he impact of eye movements and ftxation on the parietal visual cortex Convergence and attentive fixation will also enhance the responsiveness of light-sensitive parietal visual neurons (PVNs) in area PG of the

posterior parietal cortex 50 In experiments where monkeys are trained to fix their attention on a screen-and to keep on fixating even if no targets appearshythe excitability of these light-sensitive PVNs increases by as much as 350 51

52-53Responsiveness is also facilitated by the angle of gaze Also area PG is the first region in the visual pathways containing individual neurons with the capacity to respond to large bilateral stimuli moving in opposite directions along the central meridians of vision (opponent vector motion) 853-55 Facilitation of PVNs in area PG has the effect of sensitizing the subject to bilateral opponent vector motion and this is especially true if the movement appears in the periphery of the VE 8

Intracortical ampliftcation and feedback to the LGN When PGO waves and signals from the SC arrive in the primary visual cortex they may be relatively weak however weak signals can be amplified by reverberating in large networks

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 139

of cortical cells linked by local projection 56 There are nine times as many excitatory links among cortical cells as there are projections from the visual cortex to the LGN an imbalance which suggests leads Suarez Koch and Douglas to propose that geniculate input provides only a minor fraction of the excitatory input the majority originating in neighboring and recurrently connected cortical cells57 If the excitabiliry of cortical neurons is slightly higher than normal then this process of amplification may continue even after the LGN signals that initiated the reverberation are no longer being transmitted by the LGN ( a hysteretic mode of operation) 57

Feedback from hyperexcited cortical neurons will stream back to the LGN via corticogeniculate projections which outnumber geniculocortical projections ten-to-one One effect of this feedback is that the LGN is

able to absorb large amounts of information flowing back from the cortex 58

As signals reverberate back and forth in thalamocorticothalamic circuits a matching process takes place those geniculate relay cells that fire in patterns consistent with the firing patterns of active cortical cells will have their responshysivity enhanced while those geniculate cells that fire in patterns not consistent with cortical cells will be suppressed 59

Preservation of consciousness by selective facilitation of the visual pathways By combining all of the facilitatory effects produced by the authors eye movements and attentive fixation-(l) stimulation of the LGN by feedback from periorbital proprioception both directly and indirectly via the SC (2) the release of PGO waves (EMPs) that facilitate neurons in the LGN and primary visual cortex as they pass (3) the facilitation of the primary visual cortex by a state of relaxed immobile expectancy (4) attentive fixation and angle of gaze that facilitate PVNs in area PG (5) intracortical amplification of signals received from the LGN and (6) corticogeniculate feedback that stimulates the LGN-we delineate a circuit of enhanced excitability that extends from the LGN through the post-geniculate visual heirarchy to area PG where signals are integrated into representations of objects

The hyperexcitability of neurons all along the post-geniculate visual pathways creates conditions in the visual cortices which are similar to those present during EEG-desynchronized states of waking and REMS Therefore neurons in the visual pathways are too excitable to be entrained by synchronous bursting

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 140

patterns when spindle waves move through them instead the spindle bursts stimulate visual neurons to depolarize and then recover as happens in response to afferent sensory signals during waking states It is important to note that for this to occur none of the constituent neuron assemblies is required to perform an abnormal operation the abnormality is a function of the authors intent to activate contemporaneously neuron assemblies that would not normally be co-activated

PART IV HYPNOTIC ANALGESIA

Manipulation of spatial attention as a method for alleviating pain sensations In a theoretical article on the neurophysiology of hypnosis Crawford and Gruzelier60 propose that variations in hypnotizability are function of variability in the efficiency of the frontolimbic (anterior) attentional system in humans high-hypnotizables are better able to sustain focused attention on a task and to ignore extraneous stimuli than are low-hypnotizables

I na related empirical study that compares the use of attention by subjects with high versus low hypnotizability Crawford Brown and Moon61 report that highly hypnotizable persons continue to show physiological reactivity

while cognitively not perceiving the painful stimuli Through disattentional processes they can dissociate themselves from the awareness of pain The authors phosphene induction behaviors-and the cutaneous analgesia he experishyences-appear to involve the same kind of behaviors that is a mobilization of frontolimbic attention used to withdraw attention from external stimuli and to concentrate it on internally-generated phosphene images This suggests the hypothesis that the mechanisms that generate phosphenes might also produce hypnotic analgesia There are several ways that visual signals and pain signals might interact to produce this analgesia

Competition between pain and vision signals for limbic registration The fully-developed sensation of pain requires integration of rwo kinds of informashytion Signals that encode the location and intensity of a noxious stimulus (nociceptive signals) are relayed via the thalamus to the somatosensory cortices which registers only the sensory-discriminative aspects of pain perception62 before reaching consciousness the nociceptive signals must be sent to the limbic

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 141

system where they are linked with signals from long-term memory that encode the affective significance the stimulus has acquired for that individual Studies of brain metabolism show this linking of somatosensory information with limbic associations takes place in the anterior cingulate (CG) and anterior insula62-64

PET studies also show that the anterior CG is activated when subjects shift their spatial attention in response to expectations as to where

66stimuli will next appear65- This is precisely what takes place during the state of immobile expectancy that induces phosphenes Since visual signals and nociceptive signals both require limbic enhancement which is only possible if they get access to the anterior CG there might be conditions in which the two types of afferent sensory signals have to compete for that access In a theoretical article on the mechanisms of attention Posner and Rothbart67

propose that visual signals can interfere with nociceptive signals by blocking access to the anterior CG As behavioral evidence they cite studies showing that when young infants make distress calls they can be distracted by the presentation of a new visual stimulus We have shown the evidence of such control at about three months Orienting to visual events can be employed to quiet or calm negative vocalizations However the distress appears to be maintained and reappears when the infants attention to the stimulus is reduced Caregivers also report the use or visual orienting to block overt manifestations of distress at about this age 67

The effects of disattention on the somatosensory cortices If there is a competition between visual signals and nociceptive signals for access to the anterior CG it is likely that the competition will be affected by the relative volume of signals received A recent study suggests that focusing attention on internally-generated visual stimuli may reduce the number of nociceptive signals relayed by the somatosensory cortices Drevets Burton Videen Snyder Simpson and Raichle68 have shown that the mere anticipation of a touch at a specific cutaneous site increases the flow of blood to those cortical somatosenshysory neurons that are linked with that site where touch is expected and decreases the flow of blood to neurons linked with sites where touch is not expected In this experiment the researchers designated touch as the behaviorally significant sensory stimulus but their findings suggest that the outcome could be reversed if the instructions were reversed if subjects were

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page J42

instructed to direct attention away from a cutaneous site where a noxious stimulus was being applied if they were instructed to relax close their eyes and concentrate on the play of phosphenes in the visual field as the behaviorally significant sensory stimulus then it would be reasonable to expect that the flow of blood would decrease to the somatosensory neurons linked with the cutaneous stimulus and that the flow of blood would increase to the visual cortices The decrease in blood flow to somatosensory neurons implies less neuronal activity which implies that fewer signals are being sent forward to the anterior CG than would have been sent if instead the subject were treating the touch as the behaviorally significant sensory stimulus If fewer pain signals arrive at the anterior it is reasonable to infer that the conscious experience of pain will be muted by the diversion of attention to internal visual stimuli

Differential impact of sleep rhythms in the visual and nonvisual thalamus There is another mechanism that might also contribute to the analgesic effect of inducing sleep rhythms PET studies show that

the thalamus is involved in the relay of nociceptive signals to the cortex63 although some confusion remains about which kinds of signals are relayed by which subregions in the thalamus62 One thalamic site clearly identified by anatomical studies as a relay for nociceptive signals is the ventroposterior lateral nucleus (VPL)69 If synchronous sleep rhythms are active in the thalamus we can reasonably expect that the VPL will itself be entrained by synchronous oscillations and that it will relay the sleep rhythms to somatosensory cortices Relay neurons in the VPL are not stimulated by feedback from eye movements and fixation as are relay neurons in the LGN which suggests that sleep rhythms may impede the relay of nociceptive signals via the VPL but not the relay of visual signals via the LGN

Brain waves associated with anesthesia and NREMS The hypothesis presented here-that consciousness can be preserved despite the presence of NREMS activity-is consistent with a recent report that the kinds of fast brain waves which are normally associated with conscious states are also present during NREMS and anesthesia two states which were thought to involve minimal brain activityJo Another recent study found that there is a close resemblance between the slow brain waves that appear during NREMS and those that appear during certain types of anesthesia71

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 143

bull bull bull

CONCLUSION

In this paper we have presented evidence supporting the hypothesis that phosphene images can be generated as an epiphenomena of thalamic spindle bursts and delta wave activity normally associated with NREMS The prereqshyuisites for inducing these sleep rhythm phosphenes are relaxed immobile expectancy sustained convergence and attentive fixation of an undifferentiated visual field Our hypothesis provides a necessary and sufficient explanation for the authors induction of phosphenes and perhaps also for the generation of phosphenes reported to appear spontaneously during the drowsy transition to sleep (hypnagogic states) during sensory deprivation or during certain kinds of prayer or meditation all of which involve a similar state of relaxed immobile expectancyJ2

CORRESPONDENCE Philip T Nicholson bull 52 Norfolk Road bull Chestnut Hill MA 02167

REFERENCES amp NOTES

1 M 1 Posner Modulation by Instruction Nature 373 (1995) pp 198-199 2 J Reissenweber E David amp M pfotenhauer Investigations of Psychological Aspects of

the Perception of Magnetophosphenes and Electrophosphenes Biomedizinische Tecknik 373 (1992) pp 42-45

3 S M Kosslyn W L Thompson 1 J Kim amp N M Alpert Topographical Representations of Mental Images in Primary Visual Cortex Nature 378 (I995) pp 496-498

4 P E Roland amp B Gulyas Visual Memory Visual Imagery and Visual Recognition of Large Field Patterns by the Human Brain Functional Anatomy by Positron Emission Tomography Cerebral Cortex 51 (1995) pp 79-93

5 H Benson The Relaxation Response (Morrow New York NY 1975) 6 ] H Schultz amp W Luthe Autogenic Training a Physiological Approach to Psychotherapy

(Grune amp Stratton New York NY 1969) 7 E Jacobson Progressive Relaxation (University of Chicago Press Chicago IL 1938) 8 M A Steinmetz BC Motter C] DuffY amp V B Mountcastle Functional Properties

of Parietal Visual Neurons Radial Organization of Directionalities Within the Visual Field Journal ofNeuroscience 71 (1987) pp 177-191

9 R R Edelman Magnetic Resonance Imaging of the Nervous System Discussions in Neuroscience 71 Elsevier Science Amsterdam (I990) also J H Newhouse amp ] I Wiener Understanding MRI 1st Ed (Little Brown Boston MA 1991)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 144

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

of thalamocortical cells preventing their relay of afferent sensory signals and inducing a loss of consciousness21 But the loss of consciousness cannot be timed precisely using cortical EEG the thalamus is too remote for the onset of spindling to be reliably detected by scalp electrodes39 In experiments with cats where electrodes could be implanted in the thalamus researchers found that spindling often reached peak levels of activity in the thalamus-a level of activity consonant with stage 2 NREMS-at a time when the cortical EEG was still showing intermittent desynchronizations a pattern characteristic of the drowsy stage 1 transition not a fully-established stage 2 NREMS episode4o

In other words there is a short period of time in which the synchronous rhythms of stage 2 NREMS are installed in the thalamus but not in the cortex where cortical neurons continue to depolarize in response to afferent sensory signals

T his finding suggests a possible explanation for the authors ability to retain consciousness while spindle bursts are sweeping through the LGN if he is able to extend the duration of this time lag between

the onset of spindling in the thalamus and spindling in the cortex if he is able to stimulate the visual cortices in such a way that they continue to depolarize then he may be able to keep on processing visual signals-to remain visually aware-even after the non-visual thalamus and non-visual cortex become entrained by synchronous sleep rhythms The authors induction technique includes several behaviors which are known to enhance the responsiveness of visual neurons-eye movements attentive fixation and an attitude of expectancy

Effects of eye movements and attention on the LGN Sustained convergence causes periorbital proprioceptors to send excitatory feedback directly to the LGN41 Also convergence further enhances the excitability of geniculate cells by stimulating the superior collicus (SC) which sends its own excitatory signals to the LGN42-43 These signals from the SC are known to selectively enhance the excitability of visual relay cells that represent the periphery of vision44 We know in the authors case that the SC is being stimulated because he is able to keep on fixating an ability which would normally be lost during the transishytion to NREMS45 The ability to fixate can be retained however if the SC is stimulated (even if stimulated during NREMS)46

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 138

Effects of eye movement attention and expectancy on the primary visual cortex The PET study of mental imagery by Kosslyn et al 3 showed that even a baseline resting state of relaxed immobile expectancy can generate signifishycant increases in neuronal activity in the primary visual cortices Further increases can be induced by sustained eye movements

A sustained convergence will release a stream of ponto-geniculo-occipital (PGO) waves These PGO waves called eye movement potentials or EMPs last only as long as the eye movement1747 whereas the PGO waves associated with rapid-eye-movement sleep (REMS) fire continually for the duration of the REMS episode Both REMS-related PGO waves and EMPs have the same desynchronizing effect on the visual pathways they move through the LGN depolarizing the thalamocortical cells which relay the signals to cortical neurons The responsivity of neurons in the primary visual cortices is enhanced by the stimulation of PGO waves 1747-49 If the passage of EMPs causes the genicushylate relay cells and their cortical targets to depolarize regularly then a volley of 4 spindle bursts moving through the same pathways will register as just another series of depolarizations in effect the spindle bursts are processed by the visual system as if they were sensory signals sent from the retina rather than an event stimulated by endogenous mechanisms

T he impact of eye movements and ftxation on the parietal visual cortex Convergence and attentive fixation will also enhance the responsiveness of light-sensitive parietal visual neurons (PVNs) in area PG of the

posterior parietal cortex 50 In experiments where monkeys are trained to fix their attention on a screen-and to keep on fixating even if no targets appearshythe excitability of these light-sensitive PVNs increases by as much as 350 51

52-53Responsiveness is also facilitated by the angle of gaze Also area PG is the first region in the visual pathways containing individual neurons with the capacity to respond to large bilateral stimuli moving in opposite directions along the central meridians of vision (opponent vector motion) 853-55 Facilitation of PVNs in area PG has the effect of sensitizing the subject to bilateral opponent vector motion and this is especially true if the movement appears in the periphery of the VE 8

Intracortical ampliftcation and feedback to the LGN When PGO waves and signals from the SC arrive in the primary visual cortex they may be relatively weak however weak signals can be amplified by reverberating in large networks

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 139

of cortical cells linked by local projection 56 There are nine times as many excitatory links among cortical cells as there are projections from the visual cortex to the LGN an imbalance which suggests leads Suarez Koch and Douglas to propose that geniculate input provides only a minor fraction of the excitatory input the majority originating in neighboring and recurrently connected cortical cells57 If the excitabiliry of cortical neurons is slightly higher than normal then this process of amplification may continue even after the LGN signals that initiated the reverberation are no longer being transmitted by the LGN ( a hysteretic mode of operation) 57

Feedback from hyperexcited cortical neurons will stream back to the LGN via corticogeniculate projections which outnumber geniculocortical projections ten-to-one One effect of this feedback is that the LGN is

able to absorb large amounts of information flowing back from the cortex 58

As signals reverberate back and forth in thalamocorticothalamic circuits a matching process takes place those geniculate relay cells that fire in patterns consistent with the firing patterns of active cortical cells will have their responshysivity enhanced while those geniculate cells that fire in patterns not consistent with cortical cells will be suppressed 59

Preservation of consciousness by selective facilitation of the visual pathways By combining all of the facilitatory effects produced by the authors eye movements and attentive fixation-(l) stimulation of the LGN by feedback from periorbital proprioception both directly and indirectly via the SC (2) the release of PGO waves (EMPs) that facilitate neurons in the LGN and primary visual cortex as they pass (3) the facilitation of the primary visual cortex by a state of relaxed immobile expectancy (4) attentive fixation and angle of gaze that facilitate PVNs in area PG (5) intracortical amplification of signals received from the LGN and (6) corticogeniculate feedback that stimulates the LGN-we delineate a circuit of enhanced excitability that extends from the LGN through the post-geniculate visual heirarchy to area PG where signals are integrated into representations of objects

The hyperexcitability of neurons all along the post-geniculate visual pathways creates conditions in the visual cortices which are similar to those present during EEG-desynchronized states of waking and REMS Therefore neurons in the visual pathways are too excitable to be entrained by synchronous bursting

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 140

patterns when spindle waves move through them instead the spindle bursts stimulate visual neurons to depolarize and then recover as happens in response to afferent sensory signals during waking states It is important to note that for this to occur none of the constituent neuron assemblies is required to perform an abnormal operation the abnormality is a function of the authors intent to activate contemporaneously neuron assemblies that would not normally be co-activated

PART IV HYPNOTIC ANALGESIA

Manipulation of spatial attention as a method for alleviating pain sensations In a theoretical article on the neurophysiology of hypnosis Crawford and Gruzelier60 propose that variations in hypnotizability are function of variability in the efficiency of the frontolimbic (anterior) attentional system in humans high-hypnotizables are better able to sustain focused attention on a task and to ignore extraneous stimuli than are low-hypnotizables

I na related empirical study that compares the use of attention by subjects with high versus low hypnotizability Crawford Brown and Moon61 report that highly hypnotizable persons continue to show physiological reactivity

while cognitively not perceiving the painful stimuli Through disattentional processes they can dissociate themselves from the awareness of pain The authors phosphene induction behaviors-and the cutaneous analgesia he experishyences-appear to involve the same kind of behaviors that is a mobilization of frontolimbic attention used to withdraw attention from external stimuli and to concentrate it on internally-generated phosphene images This suggests the hypothesis that the mechanisms that generate phosphenes might also produce hypnotic analgesia There are several ways that visual signals and pain signals might interact to produce this analgesia

Competition between pain and vision signals for limbic registration The fully-developed sensation of pain requires integration of rwo kinds of informashytion Signals that encode the location and intensity of a noxious stimulus (nociceptive signals) are relayed via the thalamus to the somatosensory cortices which registers only the sensory-discriminative aspects of pain perception62 before reaching consciousness the nociceptive signals must be sent to the limbic

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 141

system where they are linked with signals from long-term memory that encode the affective significance the stimulus has acquired for that individual Studies of brain metabolism show this linking of somatosensory information with limbic associations takes place in the anterior cingulate (CG) and anterior insula62-64

PET studies also show that the anterior CG is activated when subjects shift their spatial attention in response to expectations as to where

66stimuli will next appear65- This is precisely what takes place during the state of immobile expectancy that induces phosphenes Since visual signals and nociceptive signals both require limbic enhancement which is only possible if they get access to the anterior CG there might be conditions in which the two types of afferent sensory signals have to compete for that access In a theoretical article on the mechanisms of attention Posner and Rothbart67

propose that visual signals can interfere with nociceptive signals by blocking access to the anterior CG As behavioral evidence they cite studies showing that when young infants make distress calls they can be distracted by the presentation of a new visual stimulus We have shown the evidence of such control at about three months Orienting to visual events can be employed to quiet or calm negative vocalizations However the distress appears to be maintained and reappears when the infants attention to the stimulus is reduced Caregivers also report the use or visual orienting to block overt manifestations of distress at about this age 67

The effects of disattention on the somatosensory cortices If there is a competition between visual signals and nociceptive signals for access to the anterior CG it is likely that the competition will be affected by the relative volume of signals received A recent study suggests that focusing attention on internally-generated visual stimuli may reduce the number of nociceptive signals relayed by the somatosensory cortices Drevets Burton Videen Snyder Simpson and Raichle68 have shown that the mere anticipation of a touch at a specific cutaneous site increases the flow of blood to those cortical somatosenshysory neurons that are linked with that site where touch is expected and decreases the flow of blood to neurons linked with sites where touch is not expected In this experiment the researchers designated touch as the behaviorally significant sensory stimulus but their findings suggest that the outcome could be reversed if the instructions were reversed if subjects were

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page J42

instructed to direct attention away from a cutaneous site where a noxious stimulus was being applied if they were instructed to relax close their eyes and concentrate on the play of phosphenes in the visual field as the behaviorally significant sensory stimulus then it would be reasonable to expect that the flow of blood would decrease to the somatosensory neurons linked with the cutaneous stimulus and that the flow of blood would increase to the visual cortices The decrease in blood flow to somatosensory neurons implies less neuronal activity which implies that fewer signals are being sent forward to the anterior CG than would have been sent if instead the subject were treating the touch as the behaviorally significant sensory stimulus If fewer pain signals arrive at the anterior it is reasonable to infer that the conscious experience of pain will be muted by the diversion of attention to internal visual stimuli

Differential impact of sleep rhythms in the visual and nonvisual thalamus There is another mechanism that might also contribute to the analgesic effect of inducing sleep rhythms PET studies show that

the thalamus is involved in the relay of nociceptive signals to the cortex63 although some confusion remains about which kinds of signals are relayed by which subregions in the thalamus62 One thalamic site clearly identified by anatomical studies as a relay for nociceptive signals is the ventroposterior lateral nucleus (VPL)69 If synchronous sleep rhythms are active in the thalamus we can reasonably expect that the VPL will itself be entrained by synchronous oscillations and that it will relay the sleep rhythms to somatosensory cortices Relay neurons in the VPL are not stimulated by feedback from eye movements and fixation as are relay neurons in the LGN which suggests that sleep rhythms may impede the relay of nociceptive signals via the VPL but not the relay of visual signals via the LGN

Brain waves associated with anesthesia and NREMS The hypothesis presented here-that consciousness can be preserved despite the presence of NREMS activity-is consistent with a recent report that the kinds of fast brain waves which are normally associated with conscious states are also present during NREMS and anesthesia two states which were thought to involve minimal brain activityJo Another recent study found that there is a close resemblance between the slow brain waves that appear during NREMS and those that appear during certain types of anesthesia71

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 143

bull bull bull

CONCLUSION

In this paper we have presented evidence supporting the hypothesis that phosphene images can be generated as an epiphenomena of thalamic spindle bursts and delta wave activity normally associated with NREMS The prereqshyuisites for inducing these sleep rhythm phosphenes are relaxed immobile expectancy sustained convergence and attentive fixation of an undifferentiated visual field Our hypothesis provides a necessary and sufficient explanation for the authors induction of phosphenes and perhaps also for the generation of phosphenes reported to appear spontaneously during the drowsy transition to sleep (hypnagogic states) during sensory deprivation or during certain kinds of prayer or meditation all of which involve a similar state of relaxed immobile expectancyJ2

CORRESPONDENCE Philip T Nicholson bull 52 Norfolk Road bull Chestnut Hill MA 02167

REFERENCES amp NOTES

1 M 1 Posner Modulation by Instruction Nature 373 (1995) pp 198-199 2 J Reissenweber E David amp M pfotenhauer Investigations of Psychological Aspects of

the Perception of Magnetophosphenes and Electrophosphenes Biomedizinische Tecknik 373 (1992) pp 42-45

3 S M Kosslyn W L Thompson 1 J Kim amp N M Alpert Topographical Representations of Mental Images in Primary Visual Cortex Nature 378 (I995) pp 496-498

4 P E Roland amp B Gulyas Visual Memory Visual Imagery and Visual Recognition of Large Field Patterns by the Human Brain Functional Anatomy by Positron Emission Tomography Cerebral Cortex 51 (1995) pp 79-93

5 H Benson The Relaxation Response (Morrow New York NY 1975) 6 ] H Schultz amp W Luthe Autogenic Training a Physiological Approach to Psychotherapy

(Grune amp Stratton New York NY 1969) 7 E Jacobson Progressive Relaxation (University of Chicago Press Chicago IL 1938) 8 M A Steinmetz BC Motter C] DuffY amp V B Mountcastle Functional Properties

of Parietal Visual Neurons Radial Organization of Directionalities Within the Visual Field Journal ofNeuroscience 71 (1987) pp 177-191

9 R R Edelman Magnetic Resonance Imaging of the Nervous System Discussions in Neuroscience 71 Elsevier Science Amsterdam (I990) also J H Newhouse amp ] I Wiener Understanding MRI 1st Ed (Little Brown Boston MA 1991)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 144

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

Effects of eye movement attention and expectancy on the primary visual cortex The PET study of mental imagery by Kosslyn et al 3 showed that even a baseline resting state of relaxed immobile expectancy can generate signifishycant increases in neuronal activity in the primary visual cortices Further increases can be induced by sustained eye movements

A sustained convergence will release a stream of ponto-geniculo-occipital (PGO) waves These PGO waves called eye movement potentials or EMPs last only as long as the eye movement1747 whereas the PGO waves associated with rapid-eye-movement sleep (REMS) fire continually for the duration of the REMS episode Both REMS-related PGO waves and EMPs have the same desynchronizing effect on the visual pathways they move through the LGN depolarizing the thalamocortical cells which relay the signals to cortical neurons The responsivity of neurons in the primary visual cortices is enhanced by the stimulation of PGO waves 1747-49 If the passage of EMPs causes the genicushylate relay cells and their cortical targets to depolarize regularly then a volley of 4 spindle bursts moving through the same pathways will register as just another series of depolarizations in effect the spindle bursts are processed by the visual system as if they were sensory signals sent from the retina rather than an event stimulated by endogenous mechanisms

T he impact of eye movements and ftxation on the parietal visual cortex Convergence and attentive fixation will also enhance the responsiveness of light-sensitive parietal visual neurons (PVNs) in area PG of the

posterior parietal cortex 50 In experiments where monkeys are trained to fix their attention on a screen-and to keep on fixating even if no targets appearshythe excitability of these light-sensitive PVNs increases by as much as 350 51

52-53Responsiveness is also facilitated by the angle of gaze Also area PG is the first region in the visual pathways containing individual neurons with the capacity to respond to large bilateral stimuli moving in opposite directions along the central meridians of vision (opponent vector motion) 853-55 Facilitation of PVNs in area PG has the effect of sensitizing the subject to bilateral opponent vector motion and this is especially true if the movement appears in the periphery of the VE 8

Intracortical ampliftcation and feedback to the LGN When PGO waves and signals from the SC arrive in the primary visual cortex they may be relatively weak however weak signals can be amplified by reverberating in large networks

Subtle Energies amp Energy Medicine bull Volume 1 bull Number 2 bull Page 139

of cortical cells linked by local projection 56 There are nine times as many excitatory links among cortical cells as there are projections from the visual cortex to the LGN an imbalance which suggests leads Suarez Koch and Douglas to propose that geniculate input provides only a minor fraction of the excitatory input the majority originating in neighboring and recurrently connected cortical cells57 If the excitabiliry of cortical neurons is slightly higher than normal then this process of amplification may continue even after the LGN signals that initiated the reverberation are no longer being transmitted by the LGN ( a hysteretic mode of operation) 57

Feedback from hyperexcited cortical neurons will stream back to the LGN via corticogeniculate projections which outnumber geniculocortical projections ten-to-one One effect of this feedback is that the LGN is

able to absorb large amounts of information flowing back from the cortex 58

As signals reverberate back and forth in thalamocorticothalamic circuits a matching process takes place those geniculate relay cells that fire in patterns consistent with the firing patterns of active cortical cells will have their responshysivity enhanced while those geniculate cells that fire in patterns not consistent with cortical cells will be suppressed 59

Preservation of consciousness by selective facilitation of the visual pathways By combining all of the facilitatory effects produced by the authors eye movements and attentive fixation-(l) stimulation of the LGN by feedback from periorbital proprioception both directly and indirectly via the SC (2) the release of PGO waves (EMPs) that facilitate neurons in the LGN and primary visual cortex as they pass (3) the facilitation of the primary visual cortex by a state of relaxed immobile expectancy (4) attentive fixation and angle of gaze that facilitate PVNs in area PG (5) intracortical amplification of signals received from the LGN and (6) corticogeniculate feedback that stimulates the LGN-we delineate a circuit of enhanced excitability that extends from the LGN through the post-geniculate visual heirarchy to area PG where signals are integrated into representations of objects

The hyperexcitability of neurons all along the post-geniculate visual pathways creates conditions in the visual cortices which are similar to those present during EEG-desynchronized states of waking and REMS Therefore neurons in the visual pathways are too excitable to be entrained by synchronous bursting

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 140

patterns when spindle waves move through them instead the spindle bursts stimulate visual neurons to depolarize and then recover as happens in response to afferent sensory signals during waking states It is important to note that for this to occur none of the constituent neuron assemblies is required to perform an abnormal operation the abnormality is a function of the authors intent to activate contemporaneously neuron assemblies that would not normally be co-activated

PART IV HYPNOTIC ANALGESIA

Manipulation of spatial attention as a method for alleviating pain sensations In a theoretical article on the neurophysiology of hypnosis Crawford and Gruzelier60 propose that variations in hypnotizability are function of variability in the efficiency of the frontolimbic (anterior) attentional system in humans high-hypnotizables are better able to sustain focused attention on a task and to ignore extraneous stimuli than are low-hypnotizables

I na related empirical study that compares the use of attention by subjects with high versus low hypnotizability Crawford Brown and Moon61 report that highly hypnotizable persons continue to show physiological reactivity

while cognitively not perceiving the painful stimuli Through disattentional processes they can dissociate themselves from the awareness of pain The authors phosphene induction behaviors-and the cutaneous analgesia he experishyences-appear to involve the same kind of behaviors that is a mobilization of frontolimbic attention used to withdraw attention from external stimuli and to concentrate it on internally-generated phosphene images This suggests the hypothesis that the mechanisms that generate phosphenes might also produce hypnotic analgesia There are several ways that visual signals and pain signals might interact to produce this analgesia

Competition between pain and vision signals for limbic registration The fully-developed sensation of pain requires integration of rwo kinds of informashytion Signals that encode the location and intensity of a noxious stimulus (nociceptive signals) are relayed via the thalamus to the somatosensory cortices which registers only the sensory-discriminative aspects of pain perception62 before reaching consciousness the nociceptive signals must be sent to the limbic

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 141

system where they are linked with signals from long-term memory that encode the affective significance the stimulus has acquired for that individual Studies of brain metabolism show this linking of somatosensory information with limbic associations takes place in the anterior cingulate (CG) and anterior insula62-64

PET studies also show that the anterior CG is activated when subjects shift their spatial attention in response to expectations as to where

66stimuli will next appear65- This is precisely what takes place during the state of immobile expectancy that induces phosphenes Since visual signals and nociceptive signals both require limbic enhancement which is only possible if they get access to the anterior CG there might be conditions in which the two types of afferent sensory signals have to compete for that access In a theoretical article on the mechanisms of attention Posner and Rothbart67

propose that visual signals can interfere with nociceptive signals by blocking access to the anterior CG As behavioral evidence they cite studies showing that when young infants make distress calls they can be distracted by the presentation of a new visual stimulus We have shown the evidence of such control at about three months Orienting to visual events can be employed to quiet or calm negative vocalizations However the distress appears to be maintained and reappears when the infants attention to the stimulus is reduced Caregivers also report the use or visual orienting to block overt manifestations of distress at about this age 67

The effects of disattention on the somatosensory cortices If there is a competition between visual signals and nociceptive signals for access to the anterior CG it is likely that the competition will be affected by the relative volume of signals received A recent study suggests that focusing attention on internally-generated visual stimuli may reduce the number of nociceptive signals relayed by the somatosensory cortices Drevets Burton Videen Snyder Simpson and Raichle68 have shown that the mere anticipation of a touch at a specific cutaneous site increases the flow of blood to those cortical somatosenshysory neurons that are linked with that site where touch is expected and decreases the flow of blood to neurons linked with sites where touch is not expected In this experiment the researchers designated touch as the behaviorally significant sensory stimulus but their findings suggest that the outcome could be reversed if the instructions were reversed if subjects were

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page J42

instructed to direct attention away from a cutaneous site where a noxious stimulus was being applied if they were instructed to relax close their eyes and concentrate on the play of phosphenes in the visual field as the behaviorally significant sensory stimulus then it would be reasonable to expect that the flow of blood would decrease to the somatosensory neurons linked with the cutaneous stimulus and that the flow of blood would increase to the visual cortices The decrease in blood flow to somatosensory neurons implies less neuronal activity which implies that fewer signals are being sent forward to the anterior CG than would have been sent if instead the subject were treating the touch as the behaviorally significant sensory stimulus If fewer pain signals arrive at the anterior it is reasonable to infer that the conscious experience of pain will be muted by the diversion of attention to internal visual stimuli

Differential impact of sleep rhythms in the visual and nonvisual thalamus There is another mechanism that might also contribute to the analgesic effect of inducing sleep rhythms PET studies show that

the thalamus is involved in the relay of nociceptive signals to the cortex63 although some confusion remains about which kinds of signals are relayed by which subregions in the thalamus62 One thalamic site clearly identified by anatomical studies as a relay for nociceptive signals is the ventroposterior lateral nucleus (VPL)69 If synchronous sleep rhythms are active in the thalamus we can reasonably expect that the VPL will itself be entrained by synchronous oscillations and that it will relay the sleep rhythms to somatosensory cortices Relay neurons in the VPL are not stimulated by feedback from eye movements and fixation as are relay neurons in the LGN which suggests that sleep rhythms may impede the relay of nociceptive signals via the VPL but not the relay of visual signals via the LGN

Brain waves associated with anesthesia and NREMS The hypothesis presented here-that consciousness can be preserved despite the presence of NREMS activity-is consistent with a recent report that the kinds of fast brain waves which are normally associated with conscious states are also present during NREMS and anesthesia two states which were thought to involve minimal brain activityJo Another recent study found that there is a close resemblance between the slow brain waves that appear during NREMS and those that appear during certain types of anesthesia71

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 143

bull bull bull

CONCLUSION

In this paper we have presented evidence supporting the hypothesis that phosphene images can be generated as an epiphenomena of thalamic spindle bursts and delta wave activity normally associated with NREMS The prereqshyuisites for inducing these sleep rhythm phosphenes are relaxed immobile expectancy sustained convergence and attentive fixation of an undifferentiated visual field Our hypothesis provides a necessary and sufficient explanation for the authors induction of phosphenes and perhaps also for the generation of phosphenes reported to appear spontaneously during the drowsy transition to sleep (hypnagogic states) during sensory deprivation or during certain kinds of prayer or meditation all of which involve a similar state of relaxed immobile expectancyJ2

CORRESPONDENCE Philip T Nicholson bull 52 Norfolk Road bull Chestnut Hill MA 02167

REFERENCES amp NOTES

1 M 1 Posner Modulation by Instruction Nature 373 (1995) pp 198-199 2 J Reissenweber E David amp M pfotenhauer Investigations of Psychological Aspects of

the Perception of Magnetophosphenes and Electrophosphenes Biomedizinische Tecknik 373 (1992) pp 42-45

3 S M Kosslyn W L Thompson 1 J Kim amp N M Alpert Topographical Representations of Mental Images in Primary Visual Cortex Nature 378 (I995) pp 496-498

4 P E Roland amp B Gulyas Visual Memory Visual Imagery and Visual Recognition of Large Field Patterns by the Human Brain Functional Anatomy by Positron Emission Tomography Cerebral Cortex 51 (1995) pp 79-93

5 H Benson The Relaxation Response (Morrow New York NY 1975) 6 ] H Schultz amp W Luthe Autogenic Training a Physiological Approach to Psychotherapy

(Grune amp Stratton New York NY 1969) 7 E Jacobson Progressive Relaxation (University of Chicago Press Chicago IL 1938) 8 M A Steinmetz BC Motter C] DuffY amp V B Mountcastle Functional Properties

of Parietal Visual Neurons Radial Organization of Directionalities Within the Visual Field Journal ofNeuroscience 71 (1987) pp 177-191

9 R R Edelman Magnetic Resonance Imaging of the Nervous System Discussions in Neuroscience 71 Elsevier Science Amsterdam (I990) also J H Newhouse amp ] I Wiener Understanding MRI 1st Ed (Little Brown Boston MA 1991)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 144

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

of cortical cells linked by local projection 56 There are nine times as many excitatory links among cortical cells as there are projections from the visual cortex to the LGN an imbalance which suggests leads Suarez Koch and Douglas to propose that geniculate input provides only a minor fraction of the excitatory input the majority originating in neighboring and recurrently connected cortical cells57 If the excitabiliry of cortical neurons is slightly higher than normal then this process of amplification may continue even after the LGN signals that initiated the reverberation are no longer being transmitted by the LGN ( a hysteretic mode of operation) 57

Feedback from hyperexcited cortical neurons will stream back to the LGN via corticogeniculate projections which outnumber geniculocortical projections ten-to-one One effect of this feedback is that the LGN is

able to absorb large amounts of information flowing back from the cortex 58

As signals reverberate back and forth in thalamocorticothalamic circuits a matching process takes place those geniculate relay cells that fire in patterns consistent with the firing patterns of active cortical cells will have their responshysivity enhanced while those geniculate cells that fire in patterns not consistent with cortical cells will be suppressed 59

Preservation of consciousness by selective facilitation of the visual pathways By combining all of the facilitatory effects produced by the authors eye movements and attentive fixation-(l) stimulation of the LGN by feedback from periorbital proprioception both directly and indirectly via the SC (2) the release of PGO waves (EMPs) that facilitate neurons in the LGN and primary visual cortex as they pass (3) the facilitation of the primary visual cortex by a state of relaxed immobile expectancy (4) attentive fixation and angle of gaze that facilitate PVNs in area PG (5) intracortical amplification of signals received from the LGN and (6) corticogeniculate feedback that stimulates the LGN-we delineate a circuit of enhanced excitability that extends from the LGN through the post-geniculate visual heirarchy to area PG where signals are integrated into representations of objects

The hyperexcitability of neurons all along the post-geniculate visual pathways creates conditions in the visual cortices which are similar to those present during EEG-desynchronized states of waking and REMS Therefore neurons in the visual pathways are too excitable to be entrained by synchronous bursting

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 140

patterns when spindle waves move through them instead the spindle bursts stimulate visual neurons to depolarize and then recover as happens in response to afferent sensory signals during waking states It is important to note that for this to occur none of the constituent neuron assemblies is required to perform an abnormal operation the abnormality is a function of the authors intent to activate contemporaneously neuron assemblies that would not normally be co-activated

PART IV HYPNOTIC ANALGESIA

Manipulation of spatial attention as a method for alleviating pain sensations In a theoretical article on the neurophysiology of hypnosis Crawford and Gruzelier60 propose that variations in hypnotizability are function of variability in the efficiency of the frontolimbic (anterior) attentional system in humans high-hypnotizables are better able to sustain focused attention on a task and to ignore extraneous stimuli than are low-hypnotizables

I na related empirical study that compares the use of attention by subjects with high versus low hypnotizability Crawford Brown and Moon61 report that highly hypnotizable persons continue to show physiological reactivity

while cognitively not perceiving the painful stimuli Through disattentional processes they can dissociate themselves from the awareness of pain The authors phosphene induction behaviors-and the cutaneous analgesia he experishyences-appear to involve the same kind of behaviors that is a mobilization of frontolimbic attention used to withdraw attention from external stimuli and to concentrate it on internally-generated phosphene images This suggests the hypothesis that the mechanisms that generate phosphenes might also produce hypnotic analgesia There are several ways that visual signals and pain signals might interact to produce this analgesia

Competition between pain and vision signals for limbic registration The fully-developed sensation of pain requires integration of rwo kinds of informashytion Signals that encode the location and intensity of a noxious stimulus (nociceptive signals) are relayed via the thalamus to the somatosensory cortices which registers only the sensory-discriminative aspects of pain perception62 before reaching consciousness the nociceptive signals must be sent to the limbic

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 141

system where they are linked with signals from long-term memory that encode the affective significance the stimulus has acquired for that individual Studies of brain metabolism show this linking of somatosensory information with limbic associations takes place in the anterior cingulate (CG) and anterior insula62-64

PET studies also show that the anterior CG is activated when subjects shift their spatial attention in response to expectations as to where

66stimuli will next appear65- This is precisely what takes place during the state of immobile expectancy that induces phosphenes Since visual signals and nociceptive signals both require limbic enhancement which is only possible if they get access to the anterior CG there might be conditions in which the two types of afferent sensory signals have to compete for that access In a theoretical article on the mechanisms of attention Posner and Rothbart67

propose that visual signals can interfere with nociceptive signals by blocking access to the anterior CG As behavioral evidence they cite studies showing that when young infants make distress calls they can be distracted by the presentation of a new visual stimulus We have shown the evidence of such control at about three months Orienting to visual events can be employed to quiet or calm negative vocalizations However the distress appears to be maintained and reappears when the infants attention to the stimulus is reduced Caregivers also report the use or visual orienting to block overt manifestations of distress at about this age 67

The effects of disattention on the somatosensory cortices If there is a competition between visual signals and nociceptive signals for access to the anterior CG it is likely that the competition will be affected by the relative volume of signals received A recent study suggests that focusing attention on internally-generated visual stimuli may reduce the number of nociceptive signals relayed by the somatosensory cortices Drevets Burton Videen Snyder Simpson and Raichle68 have shown that the mere anticipation of a touch at a specific cutaneous site increases the flow of blood to those cortical somatosenshysory neurons that are linked with that site where touch is expected and decreases the flow of blood to neurons linked with sites where touch is not expected In this experiment the researchers designated touch as the behaviorally significant sensory stimulus but their findings suggest that the outcome could be reversed if the instructions were reversed if subjects were

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page J42

instructed to direct attention away from a cutaneous site where a noxious stimulus was being applied if they were instructed to relax close their eyes and concentrate on the play of phosphenes in the visual field as the behaviorally significant sensory stimulus then it would be reasonable to expect that the flow of blood would decrease to the somatosensory neurons linked with the cutaneous stimulus and that the flow of blood would increase to the visual cortices The decrease in blood flow to somatosensory neurons implies less neuronal activity which implies that fewer signals are being sent forward to the anterior CG than would have been sent if instead the subject were treating the touch as the behaviorally significant sensory stimulus If fewer pain signals arrive at the anterior it is reasonable to infer that the conscious experience of pain will be muted by the diversion of attention to internal visual stimuli

Differential impact of sleep rhythms in the visual and nonvisual thalamus There is another mechanism that might also contribute to the analgesic effect of inducing sleep rhythms PET studies show that

the thalamus is involved in the relay of nociceptive signals to the cortex63 although some confusion remains about which kinds of signals are relayed by which subregions in the thalamus62 One thalamic site clearly identified by anatomical studies as a relay for nociceptive signals is the ventroposterior lateral nucleus (VPL)69 If synchronous sleep rhythms are active in the thalamus we can reasonably expect that the VPL will itself be entrained by synchronous oscillations and that it will relay the sleep rhythms to somatosensory cortices Relay neurons in the VPL are not stimulated by feedback from eye movements and fixation as are relay neurons in the LGN which suggests that sleep rhythms may impede the relay of nociceptive signals via the VPL but not the relay of visual signals via the LGN

Brain waves associated with anesthesia and NREMS The hypothesis presented here-that consciousness can be preserved despite the presence of NREMS activity-is consistent with a recent report that the kinds of fast brain waves which are normally associated with conscious states are also present during NREMS and anesthesia two states which were thought to involve minimal brain activityJo Another recent study found that there is a close resemblance between the slow brain waves that appear during NREMS and those that appear during certain types of anesthesia71

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 143

bull bull bull

CONCLUSION

In this paper we have presented evidence supporting the hypothesis that phosphene images can be generated as an epiphenomena of thalamic spindle bursts and delta wave activity normally associated with NREMS The prereqshyuisites for inducing these sleep rhythm phosphenes are relaxed immobile expectancy sustained convergence and attentive fixation of an undifferentiated visual field Our hypothesis provides a necessary and sufficient explanation for the authors induction of phosphenes and perhaps also for the generation of phosphenes reported to appear spontaneously during the drowsy transition to sleep (hypnagogic states) during sensory deprivation or during certain kinds of prayer or meditation all of which involve a similar state of relaxed immobile expectancyJ2

CORRESPONDENCE Philip T Nicholson bull 52 Norfolk Road bull Chestnut Hill MA 02167

REFERENCES amp NOTES

1 M 1 Posner Modulation by Instruction Nature 373 (1995) pp 198-199 2 J Reissenweber E David amp M pfotenhauer Investigations of Psychological Aspects of

the Perception of Magnetophosphenes and Electrophosphenes Biomedizinische Tecknik 373 (1992) pp 42-45

3 S M Kosslyn W L Thompson 1 J Kim amp N M Alpert Topographical Representations of Mental Images in Primary Visual Cortex Nature 378 (I995) pp 496-498

4 P E Roland amp B Gulyas Visual Memory Visual Imagery and Visual Recognition of Large Field Patterns by the Human Brain Functional Anatomy by Positron Emission Tomography Cerebral Cortex 51 (1995) pp 79-93

5 H Benson The Relaxation Response (Morrow New York NY 1975) 6 ] H Schultz amp W Luthe Autogenic Training a Physiological Approach to Psychotherapy

(Grune amp Stratton New York NY 1969) 7 E Jacobson Progressive Relaxation (University of Chicago Press Chicago IL 1938) 8 M A Steinmetz BC Motter C] DuffY amp V B Mountcastle Functional Properties

of Parietal Visual Neurons Radial Organization of Directionalities Within the Visual Field Journal ofNeuroscience 71 (1987) pp 177-191

9 R R Edelman Magnetic Resonance Imaging of the Nervous System Discussions in Neuroscience 71 Elsevier Science Amsterdam (I990) also J H Newhouse amp ] I Wiener Understanding MRI 1st Ed (Little Brown Boston MA 1991)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 144

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

patterns when spindle waves move through them instead the spindle bursts stimulate visual neurons to depolarize and then recover as happens in response to afferent sensory signals during waking states It is important to note that for this to occur none of the constituent neuron assemblies is required to perform an abnormal operation the abnormality is a function of the authors intent to activate contemporaneously neuron assemblies that would not normally be co-activated

PART IV HYPNOTIC ANALGESIA

Manipulation of spatial attention as a method for alleviating pain sensations In a theoretical article on the neurophysiology of hypnosis Crawford and Gruzelier60 propose that variations in hypnotizability are function of variability in the efficiency of the frontolimbic (anterior) attentional system in humans high-hypnotizables are better able to sustain focused attention on a task and to ignore extraneous stimuli than are low-hypnotizables

I na related empirical study that compares the use of attention by subjects with high versus low hypnotizability Crawford Brown and Moon61 report that highly hypnotizable persons continue to show physiological reactivity

while cognitively not perceiving the painful stimuli Through disattentional processes they can dissociate themselves from the awareness of pain The authors phosphene induction behaviors-and the cutaneous analgesia he experishyences-appear to involve the same kind of behaviors that is a mobilization of frontolimbic attention used to withdraw attention from external stimuli and to concentrate it on internally-generated phosphene images This suggests the hypothesis that the mechanisms that generate phosphenes might also produce hypnotic analgesia There are several ways that visual signals and pain signals might interact to produce this analgesia

Competition between pain and vision signals for limbic registration The fully-developed sensation of pain requires integration of rwo kinds of informashytion Signals that encode the location and intensity of a noxious stimulus (nociceptive signals) are relayed via the thalamus to the somatosensory cortices which registers only the sensory-discriminative aspects of pain perception62 before reaching consciousness the nociceptive signals must be sent to the limbic

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 141

system where they are linked with signals from long-term memory that encode the affective significance the stimulus has acquired for that individual Studies of brain metabolism show this linking of somatosensory information with limbic associations takes place in the anterior cingulate (CG) and anterior insula62-64

PET studies also show that the anterior CG is activated when subjects shift their spatial attention in response to expectations as to where

66stimuli will next appear65- This is precisely what takes place during the state of immobile expectancy that induces phosphenes Since visual signals and nociceptive signals both require limbic enhancement which is only possible if they get access to the anterior CG there might be conditions in which the two types of afferent sensory signals have to compete for that access In a theoretical article on the mechanisms of attention Posner and Rothbart67

propose that visual signals can interfere with nociceptive signals by blocking access to the anterior CG As behavioral evidence they cite studies showing that when young infants make distress calls they can be distracted by the presentation of a new visual stimulus We have shown the evidence of such control at about three months Orienting to visual events can be employed to quiet or calm negative vocalizations However the distress appears to be maintained and reappears when the infants attention to the stimulus is reduced Caregivers also report the use or visual orienting to block overt manifestations of distress at about this age 67

The effects of disattention on the somatosensory cortices If there is a competition between visual signals and nociceptive signals for access to the anterior CG it is likely that the competition will be affected by the relative volume of signals received A recent study suggests that focusing attention on internally-generated visual stimuli may reduce the number of nociceptive signals relayed by the somatosensory cortices Drevets Burton Videen Snyder Simpson and Raichle68 have shown that the mere anticipation of a touch at a specific cutaneous site increases the flow of blood to those cortical somatosenshysory neurons that are linked with that site where touch is expected and decreases the flow of blood to neurons linked with sites where touch is not expected In this experiment the researchers designated touch as the behaviorally significant sensory stimulus but their findings suggest that the outcome could be reversed if the instructions were reversed if subjects were

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page J42

instructed to direct attention away from a cutaneous site where a noxious stimulus was being applied if they were instructed to relax close their eyes and concentrate on the play of phosphenes in the visual field as the behaviorally significant sensory stimulus then it would be reasonable to expect that the flow of blood would decrease to the somatosensory neurons linked with the cutaneous stimulus and that the flow of blood would increase to the visual cortices The decrease in blood flow to somatosensory neurons implies less neuronal activity which implies that fewer signals are being sent forward to the anterior CG than would have been sent if instead the subject were treating the touch as the behaviorally significant sensory stimulus If fewer pain signals arrive at the anterior it is reasonable to infer that the conscious experience of pain will be muted by the diversion of attention to internal visual stimuli

Differential impact of sleep rhythms in the visual and nonvisual thalamus There is another mechanism that might also contribute to the analgesic effect of inducing sleep rhythms PET studies show that

the thalamus is involved in the relay of nociceptive signals to the cortex63 although some confusion remains about which kinds of signals are relayed by which subregions in the thalamus62 One thalamic site clearly identified by anatomical studies as a relay for nociceptive signals is the ventroposterior lateral nucleus (VPL)69 If synchronous sleep rhythms are active in the thalamus we can reasonably expect that the VPL will itself be entrained by synchronous oscillations and that it will relay the sleep rhythms to somatosensory cortices Relay neurons in the VPL are not stimulated by feedback from eye movements and fixation as are relay neurons in the LGN which suggests that sleep rhythms may impede the relay of nociceptive signals via the VPL but not the relay of visual signals via the LGN

Brain waves associated with anesthesia and NREMS The hypothesis presented here-that consciousness can be preserved despite the presence of NREMS activity-is consistent with a recent report that the kinds of fast brain waves which are normally associated with conscious states are also present during NREMS and anesthesia two states which were thought to involve minimal brain activityJo Another recent study found that there is a close resemblance between the slow brain waves that appear during NREMS and those that appear during certain types of anesthesia71

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 143

bull bull bull

CONCLUSION

In this paper we have presented evidence supporting the hypothesis that phosphene images can be generated as an epiphenomena of thalamic spindle bursts and delta wave activity normally associated with NREMS The prereqshyuisites for inducing these sleep rhythm phosphenes are relaxed immobile expectancy sustained convergence and attentive fixation of an undifferentiated visual field Our hypothesis provides a necessary and sufficient explanation for the authors induction of phosphenes and perhaps also for the generation of phosphenes reported to appear spontaneously during the drowsy transition to sleep (hypnagogic states) during sensory deprivation or during certain kinds of prayer or meditation all of which involve a similar state of relaxed immobile expectancyJ2

CORRESPONDENCE Philip T Nicholson bull 52 Norfolk Road bull Chestnut Hill MA 02167

REFERENCES amp NOTES

1 M 1 Posner Modulation by Instruction Nature 373 (1995) pp 198-199 2 J Reissenweber E David amp M pfotenhauer Investigations of Psychological Aspects of

the Perception of Magnetophosphenes and Electrophosphenes Biomedizinische Tecknik 373 (1992) pp 42-45

3 S M Kosslyn W L Thompson 1 J Kim amp N M Alpert Topographical Representations of Mental Images in Primary Visual Cortex Nature 378 (I995) pp 496-498

4 P E Roland amp B Gulyas Visual Memory Visual Imagery and Visual Recognition of Large Field Patterns by the Human Brain Functional Anatomy by Positron Emission Tomography Cerebral Cortex 51 (1995) pp 79-93

5 H Benson The Relaxation Response (Morrow New York NY 1975) 6 ] H Schultz amp W Luthe Autogenic Training a Physiological Approach to Psychotherapy

(Grune amp Stratton New York NY 1969) 7 E Jacobson Progressive Relaxation (University of Chicago Press Chicago IL 1938) 8 M A Steinmetz BC Motter C] DuffY amp V B Mountcastle Functional Properties

of Parietal Visual Neurons Radial Organization of Directionalities Within the Visual Field Journal ofNeuroscience 71 (1987) pp 177-191

9 R R Edelman Magnetic Resonance Imaging of the Nervous System Discussions in Neuroscience 71 Elsevier Science Amsterdam (I990) also J H Newhouse amp ] I Wiener Understanding MRI 1st Ed (Little Brown Boston MA 1991)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 144

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

system where they are linked with signals from long-term memory that encode the affective significance the stimulus has acquired for that individual Studies of brain metabolism show this linking of somatosensory information with limbic associations takes place in the anterior cingulate (CG) and anterior insula62-64

PET studies also show that the anterior CG is activated when subjects shift their spatial attention in response to expectations as to where

66stimuli will next appear65- This is precisely what takes place during the state of immobile expectancy that induces phosphenes Since visual signals and nociceptive signals both require limbic enhancement which is only possible if they get access to the anterior CG there might be conditions in which the two types of afferent sensory signals have to compete for that access In a theoretical article on the mechanisms of attention Posner and Rothbart67

propose that visual signals can interfere with nociceptive signals by blocking access to the anterior CG As behavioral evidence they cite studies showing that when young infants make distress calls they can be distracted by the presentation of a new visual stimulus We have shown the evidence of such control at about three months Orienting to visual events can be employed to quiet or calm negative vocalizations However the distress appears to be maintained and reappears when the infants attention to the stimulus is reduced Caregivers also report the use or visual orienting to block overt manifestations of distress at about this age 67

The effects of disattention on the somatosensory cortices If there is a competition between visual signals and nociceptive signals for access to the anterior CG it is likely that the competition will be affected by the relative volume of signals received A recent study suggests that focusing attention on internally-generated visual stimuli may reduce the number of nociceptive signals relayed by the somatosensory cortices Drevets Burton Videen Snyder Simpson and Raichle68 have shown that the mere anticipation of a touch at a specific cutaneous site increases the flow of blood to those cortical somatosenshysory neurons that are linked with that site where touch is expected and decreases the flow of blood to neurons linked with sites where touch is not expected In this experiment the researchers designated touch as the behaviorally significant sensory stimulus but their findings suggest that the outcome could be reversed if the instructions were reversed if subjects were

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page J42

instructed to direct attention away from a cutaneous site where a noxious stimulus was being applied if they were instructed to relax close their eyes and concentrate on the play of phosphenes in the visual field as the behaviorally significant sensory stimulus then it would be reasonable to expect that the flow of blood would decrease to the somatosensory neurons linked with the cutaneous stimulus and that the flow of blood would increase to the visual cortices The decrease in blood flow to somatosensory neurons implies less neuronal activity which implies that fewer signals are being sent forward to the anterior CG than would have been sent if instead the subject were treating the touch as the behaviorally significant sensory stimulus If fewer pain signals arrive at the anterior it is reasonable to infer that the conscious experience of pain will be muted by the diversion of attention to internal visual stimuli

Differential impact of sleep rhythms in the visual and nonvisual thalamus There is another mechanism that might also contribute to the analgesic effect of inducing sleep rhythms PET studies show that

the thalamus is involved in the relay of nociceptive signals to the cortex63 although some confusion remains about which kinds of signals are relayed by which subregions in the thalamus62 One thalamic site clearly identified by anatomical studies as a relay for nociceptive signals is the ventroposterior lateral nucleus (VPL)69 If synchronous sleep rhythms are active in the thalamus we can reasonably expect that the VPL will itself be entrained by synchronous oscillations and that it will relay the sleep rhythms to somatosensory cortices Relay neurons in the VPL are not stimulated by feedback from eye movements and fixation as are relay neurons in the LGN which suggests that sleep rhythms may impede the relay of nociceptive signals via the VPL but not the relay of visual signals via the LGN

Brain waves associated with anesthesia and NREMS The hypothesis presented here-that consciousness can be preserved despite the presence of NREMS activity-is consistent with a recent report that the kinds of fast brain waves which are normally associated with conscious states are also present during NREMS and anesthesia two states which were thought to involve minimal brain activityJo Another recent study found that there is a close resemblance between the slow brain waves that appear during NREMS and those that appear during certain types of anesthesia71

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 143

bull bull bull

CONCLUSION

In this paper we have presented evidence supporting the hypothesis that phosphene images can be generated as an epiphenomena of thalamic spindle bursts and delta wave activity normally associated with NREMS The prereqshyuisites for inducing these sleep rhythm phosphenes are relaxed immobile expectancy sustained convergence and attentive fixation of an undifferentiated visual field Our hypothesis provides a necessary and sufficient explanation for the authors induction of phosphenes and perhaps also for the generation of phosphenes reported to appear spontaneously during the drowsy transition to sleep (hypnagogic states) during sensory deprivation or during certain kinds of prayer or meditation all of which involve a similar state of relaxed immobile expectancyJ2

CORRESPONDENCE Philip T Nicholson bull 52 Norfolk Road bull Chestnut Hill MA 02167

REFERENCES amp NOTES

1 M 1 Posner Modulation by Instruction Nature 373 (1995) pp 198-199 2 J Reissenweber E David amp M pfotenhauer Investigations of Psychological Aspects of

the Perception of Magnetophosphenes and Electrophosphenes Biomedizinische Tecknik 373 (1992) pp 42-45

3 S M Kosslyn W L Thompson 1 J Kim amp N M Alpert Topographical Representations of Mental Images in Primary Visual Cortex Nature 378 (I995) pp 496-498

4 P E Roland amp B Gulyas Visual Memory Visual Imagery and Visual Recognition of Large Field Patterns by the Human Brain Functional Anatomy by Positron Emission Tomography Cerebral Cortex 51 (1995) pp 79-93

5 H Benson The Relaxation Response (Morrow New York NY 1975) 6 ] H Schultz amp W Luthe Autogenic Training a Physiological Approach to Psychotherapy

(Grune amp Stratton New York NY 1969) 7 E Jacobson Progressive Relaxation (University of Chicago Press Chicago IL 1938) 8 M A Steinmetz BC Motter C] DuffY amp V B Mountcastle Functional Properties

of Parietal Visual Neurons Radial Organization of Directionalities Within the Visual Field Journal ofNeuroscience 71 (1987) pp 177-191

9 R R Edelman Magnetic Resonance Imaging of the Nervous System Discussions in Neuroscience 71 Elsevier Science Amsterdam (I990) also J H Newhouse amp ] I Wiener Understanding MRI 1st Ed (Little Brown Boston MA 1991)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 144

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

instructed to direct attention away from a cutaneous site where a noxious stimulus was being applied if they were instructed to relax close their eyes and concentrate on the play of phosphenes in the visual field as the behaviorally significant sensory stimulus then it would be reasonable to expect that the flow of blood would decrease to the somatosensory neurons linked with the cutaneous stimulus and that the flow of blood would increase to the visual cortices The decrease in blood flow to somatosensory neurons implies less neuronal activity which implies that fewer signals are being sent forward to the anterior CG than would have been sent if instead the subject were treating the touch as the behaviorally significant sensory stimulus If fewer pain signals arrive at the anterior it is reasonable to infer that the conscious experience of pain will be muted by the diversion of attention to internal visual stimuli

Differential impact of sleep rhythms in the visual and nonvisual thalamus There is another mechanism that might also contribute to the analgesic effect of inducing sleep rhythms PET studies show that

the thalamus is involved in the relay of nociceptive signals to the cortex63 although some confusion remains about which kinds of signals are relayed by which subregions in the thalamus62 One thalamic site clearly identified by anatomical studies as a relay for nociceptive signals is the ventroposterior lateral nucleus (VPL)69 If synchronous sleep rhythms are active in the thalamus we can reasonably expect that the VPL will itself be entrained by synchronous oscillations and that it will relay the sleep rhythms to somatosensory cortices Relay neurons in the VPL are not stimulated by feedback from eye movements and fixation as are relay neurons in the LGN which suggests that sleep rhythms may impede the relay of nociceptive signals via the VPL but not the relay of visual signals via the LGN

Brain waves associated with anesthesia and NREMS The hypothesis presented here-that consciousness can be preserved despite the presence of NREMS activity-is consistent with a recent report that the kinds of fast brain waves which are normally associated with conscious states are also present during NREMS and anesthesia two states which were thought to involve minimal brain activityJo Another recent study found that there is a close resemblance between the slow brain waves that appear during NREMS and those that appear during certain types of anesthesia71

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 143

bull bull bull

CONCLUSION

In this paper we have presented evidence supporting the hypothesis that phosphene images can be generated as an epiphenomena of thalamic spindle bursts and delta wave activity normally associated with NREMS The prereqshyuisites for inducing these sleep rhythm phosphenes are relaxed immobile expectancy sustained convergence and attentive fixation of an undifferentiated visual field Our hypothesis provides a necessary and sufficient explanation for the authors induction of phosphenes and perhaps also for the generation of phosphenes reported to appear spontaneously during the drowsy transition to sleep (hypnagogic states) during sensory deprivation or during certain kinds of prayer or meditation all of which involve a similar state of relaxed immobile expectancyJ2

CORRESPONDENCE Philip T Nicholson bull 52 Norfolk Road bull Chestnut Hill MA 02167

REFERENCES amp NOTES

1 M 1 Posner Modulation by Instruction Nature 373 (1995) pp 198-199 2 J Reissenweber E David amp M pfotenhauer Investigations of Psychological Aspects of

the Perception of Magnetophosphenes and Electrophosphenes Biomedizinische Tecknik 373 (1992) pp 42-45

3 S M Kosslyn W L Thompson 1 J Kim amp N M Alpert Topographical Representations of Mental Images in Primary Visual Cortex Nature 378 (I995) pp 496-498

4 P E Roland amp B Gulyas Visual Memory Visual Imagery and Visual Recognition of Large Field Patterns by the Human Brain Functional Anatomy by Positron Emission Tomography Cerebral Cortex 51 (1995) pp 79-93

5 H Benson The Relaxation Response (Morrow New York NY 1975) 6 ] H Schultz amp W Luthe Autogenic Training a Physiological Approach to Psychotherapy

(Grune amp Stratton New York NY 1969) 7 E Jacobson Progressive Relaxation (University of Chicago Press Chicago IL 1938) 8 M A Steinmetz BC Motter C] DuffY amp V B Mountcastle Functional Properties

of Parietal Visual Neurons Radial Organization of Directionalities Within the Visual Field Journal ofNeuroscience 71 (1987) pp 177-191

9 R R Edelman Magnetic Resonance Imaging of the Nervous System Discussions in Neuroscience 71 Elsevier Science Amsterdam (I990) also J H Newhouse amp ] I Wiener Understanding MRI 1st Ed (Little Brown Boston MA 1991)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 144

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

bull bull bull

CONCLUSION

In this paper we have presented evidence supporting the hypothesis that phosphene images can be generated as an epiphenomena of thalamic spindle bursts and delta wave activity normally associated with NREMS The prereqshyuisites for inducing these sleep rhythm phosphenes are relaxed immobile expectancy sustained convergence and attentive fixation of an undifferentiated visual field Our hypothesis provides a necessary and sufficient explanation for the authors induction of phosphenes and perhaps also for the generation of phosphenes reported to appear spontaneously during the drowsy transition to sleep (hypnagogic states) during sensory deprivation or during certain kinds of prayer or meditation all of which involve a similar state of relaxed immobile expectancyJ2

CORRESPONDENCE Philip T Nicholson bull 52 Norfolk Road bull Chestnut Hill MA 02167

REFERENCES amp NOTES

1 M 1 Posner Modulation by Instruction Nature 373 (1995) pp 198-199 2 J Reissenweber E David amp M pfotenhauer Investigations of Psychological Aspects of

the Perception of Magnetophosphenes and Electrophosphenes Biomedizinische Tecknik 373 (1992) pp 42-45

3 S M Kosslyn W L Thompson 1 J Kim amp N M Alpert Topographical Representations of Mental Images in Primary Visual Cortex Nature 378 (I995) pp 496-498

4 P E Roland amp B Gulyas Visual Memory Visual Imagery and Visual Recognition of Large Field Patterns by the Human Brain Functional Anatomy by Positron Emission Tomography Cerebral Cortex 51 (1995) pp 79-93

5 H Benson The Relaxation Response (Morrow New York NY 1975) 6 ] H Schultz amp W Luthe Autogenic Training a Physiological Approach to Psychotherapy

(Grune amp Stratton New York NY 1969) 7 E Jacobson Progressive Relaxation (University of Chicago Press Chicago IL 1938) 8 M A Steinmetz BC Motter C] DuffY amp V B Mountcastle Functional Properties

of Parietal Visual Neurons Radial Organization of Directionalities Within the Visual Field Journal ofNeuroscience 71 (1987) pp 177-191

9 R R Edelman Magnetic Resonance Imaging of the Nervous System Discussions in Neuroscience 71 Elsevier Science Amsterdam (I990) also J H Newhouse amp ] I Wiener Understanding MRI 1st Ed (Little Brown Boston MA 1991)

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 144

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

10 J W Thorpe G ]Barker S ] Jones I Moseley N Losseff D G MacManus S Webb C Mortimer D L Plummer P S Tofts W I McDonald amp D H Miller Magnetisation Transfer Ratios and Transverse Magnetisation Decay Curves in Optic Neuritis Correlation with Clinical Findings and Electrophysiology Journal of Neurology Neurosurgery and Psychiatry 59 (1995) pp 487-492

11 M J Horowitz Image Formation and Cognition (Appleton-Century-Crofts New York NY 1978)

12 J A Ardis amp P McKellar Hypnagogic Imagery and Mescaline Journal of Mental Science 102 (1956) pp 22-29

13 M Knoll Anregung Geometrischer Figuren und Anderer Subjektiver Lichtmuster in Elektrischen Feldern Sweizerische Zeitschrift fiir Psychologie und ihre Anwendungen 17 (1958) pp 1l0-126

14 M Knoll Subjective Light Pattern Spectroscopy in the Encephalographic Frequency Range Nature 184 (1959) pp 1823-1824

15 B Friedman Observations of Entoptic Phenomena Architles of Opthalmology 28 (1911) pp 285-307

16 D A McCormick amp H C Pape Properties of a Hyperpolarization-Activared Cation Current and Its Role in Rhythmic Oscillation in Thalamocortical Relay Neurons Journal of Physiology (London) 431 (1990) pp 291-318

17 M Steriade amp R W McCarley Brainstem Control of Wakefulness and Sleep (Plenum Publishing New York NY 1990)

18 M Steriade A Nufiez amp F Amzica Intracellular Analysis of Relations Between the Slow laquo 1 Hz) Neocortical Oscillation and Other Sleep Rhythms of the Electroencephalogram Journal of Neuroscience 138 (1993) pp 3266-3283

19 M Steriade D Contreras R Curro Dossi amp A Nufiez The Slow laquo 1 Hz) Oscillation in Reticular Thalamic and Thalamocortical Neurons Scenario of Sleep Rhythm Generation in Interacting Thalamic and Neocortical Networks Journal of Neuroscience 138 (1993) pp 3284-3299 also see M Steriade D A McCormick amp T SejnowskiThalamocortical Oscillations in the Sleeping and Aroused Brain Science 262 (1993) pp 679-685

20 M von Krosigk T Bal amp D A McCormick Cellular mechanisms of a synchronized Oscillation in the Thalamus Science 261 (1993) pp 361-364

21 D Contreras amp M Steriade Cellular Basis of EEG Slow Rhythms A Study of Dynamic Corticothalamic Relationships Journal ofNeuroscience 151 (1995) pp 604shy622

22 S Uchida Y Atsumi amp T Kojima Dynamic Relationships Between Sleep Spindles and Delta Waves During a NREM Period Brain Research Bulletin 33 (1994) pp 351shy355

23 W E Le Gros Clark The Laminar Organization and Cell Content of the Lateral Geniculate Body in the Monkey Journal ofAnatomy 75 (1940-41) pp 419-433

24 M Connolly amp D Van Essen The Representation of the Visual Field in Parvicellular and Magnocellular Layers of the Lateral Geniculate Nucleus in the Macaque Monkey Journal of Comparative Neurology 226 (1984) pp 544-564

25 J G Malpelli amp R H Baker The Representation of the Visual Field in the Lateral Geniculate Kucleus of Macaca Mulatta Journal of Comparative Neurology 161 (1975) pp 569-594

Subtle Energies 6- Energy Medicine bull Volume 1 bull Number 2 bull Page 145

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

26 W Kahle Color Atlas and Textbook of Human Anatomy VoL 3 Nervous System and Sensory Organs 4th ed (Georg Thieme Verlag Stuttgart Germany 1993) see also P L Williams amp R Warwick Functional Neuroanatomy ofMan (W B Saunders Philadelphia PA 1975)

27 D Pare amp M Steriade The Reticular Thalamic Nucleus Projects to the Contralateral Dorsal Thalamus in Macaque Monkeys Neuroscience Letters 154 (1993) pp 96-100

28 V Raos amp M Bentivoglio Crosstalk Between the Two Sides of the Thalamus Through the Reticular Nucleus A Retrograde and Anterograde Tracing Swdy in the Rat journal of Comparative Neurology 332 (1993) pp 145-154

29 D Contreras A Destexhe T J Sejnowski amp M Steriade Spariotemporal Patterns of Spindle Oscillations in the Cortex and Thalamus journal ofNeuroscience 173 (1997) pp 1179- 1196

30 U Kim T Bal D McCormick Spindle Waves are Propagating Synchronized Oscillations in the Ferret LGN in vitro journal of Neurophysiology 743 (1995) pp 1301-1323

31 M Knoll J Kugler O Hofer amp S D Lawder Effects of Chemical Stimulation of Electrically-Induced Phosphenes on Their Bandwidth Shape Number and Intensity Confinia Neurologia 23 (1963) pp 201-226

32 S Zeki A Vision of the Brain (Blackwell Scientific Publications London 1993) 33 J G Malpelli amp P H Schiller Lack of Blue Off-Center Cells in the Visual System of

the Monkey Brain Research 141 (l978) pp 385-389 34 P H Schiller amp J G Malpelli Functional Specificity of Lateral Geniculate Nucleus

Laminae of the Rhesus Monkey journal ofNeurophysiology 41 (1978) pp 788-797 35 D M Dacey Physiology Morphology and Spatial Densities of Identified Ganglion

Cell Types in Primate Retina In Higher-Order Processing in the Visual System (Ciba Foundation Symposia 184 John Wiley and Sons West Sussex England 1994) pp 12shy27

36 W Marks W Dobelle amp E MacNichol Visual Pigments of Simple Primate Cones Science 143 (1961) p 1181

37 B M Dow Nested Maps in Macaque Monkey Visual Cortex In Science of Vision (K N Leibovic Ed Springer-Verlag New York NY 1990) pp 84-124

38 E Maeda H P C Robinson amp A Kwana The Mechanisms of Generation and Propogation of Synchronous Bursting in Developing Networks of Cortical Neurons joumalofNeuroscience 1510 (1995) pp 6834-6845

39 M Steriade Cellular Substrates of Brain Rhythms In Electroencephalography Basic Principles Clinical Applications and Related Fields 3rd Ed (E Niedermeyer amp F Lopez da Silva Eds Williams amp Wilkins Baltimore MD 1993) pp 27-62

40 M Lancel H van Reizen amp A Glatt The Time Course of Sigma Activity and SlowshyWave Activity During NREMS in Cortical and Thalamic EEG of the Cat During Baseline and after 12 Hours of Wakefulness Brain Research 596 (1992) pp 285-295

41 l M L Donaldson amp R A Dixon Excitation of Units in the Lateral Geniculate and Contiguous Nuclei of the Cat by Stretch of the Extrinsic Ocular Muscles Experimental Brain Research 38 (1980) pp 245-255

42 M E Goldberg amp R H Wurtz Activity of Superior Colliculus in Behaving Monkey I Visual Receptive Fields of Single Neurons joumal ofNeurophysiology 35 (1972) pp 553-586

43 J S Nelson M A Meredith amp B E Stein Does an Extraocular Proprioceptive Signal Reach the Superior Colliculus joumal of Neuroscience 626 (1989) pp 1360-1374

Subtle Energies 6- Energy Medicine bull Volume 7 bull Number 2 bull Page 146

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

44 J T Xue e B Y Kim R J Moore amp P D Spear Influence of the Superior Colliculus on Responses of Lateral Geniculate Neurons in the Cat Visual Neuroscience 11 (1994) pp 1059-1076

45 V Henn R W Baloh amp K Hepp The Sleep-Wake Transition in the Oculomotor System Experimental Brain Research 54 (1984) pp 166-176

46 M S Raybourn amp E L Keller Colliculoreticular Organization in Primate Oculomotor System Joumal of Neurophysiology 404 (1977) pp 861-878

47 S Datta Neuronal Activity in the Peribrachial Area Relationship to Behavioral Srate Control Neuroscience and Biobehavioral Reviews 191 (1995) pp 67-84

48 M Steriade Alertness Quiet Sleep and Dreaming In Cerebral Cortex Vol 9 (A Peters amp E G Jones Eds Plenum Press New York NY 1991) pp 279-357

49 R H Wurtz amp e W Mohler Enhancement of Visual Responses in Monkey Striate Cortex and Frontal Eye Fields Joumal ofNeurophysiology 39 (1976) pp 766-772

50 ] S Bazier L G Ungerleider amp R Desimone Organization of Inputs to the Inferior Temporal and Posterior Parietal Cortex in Macaque Joumal of Neuroscience 111 (1991) pp 168-190

51 V B Mountcastle R A Andersen amp B e Motter The Influence of Attentive Fixation Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 111 (1981) pp 1218-1235

52 R A Andersen G K Essick amp R M Siegel Neurons of Area 7 Activated by Both Visual Stimuli and Oculomotor Behavior Experimental Brain Research 67 (1987) pp 316-322 see also R A Andersen amp V B Mountcastle The Influence of the Angle of Gaze Upon the Excitability of the Light-Sensitive Neurons of the Posterior Parietal Cortex Joumal of Neuroscience 33 (1983) pp 532-548

53 R A Andersen R M Bracewell S Barash J W Gnadt amp Fogassi L Eye Position Effects on Visual Memoty and Saccade-Related Activity in Areas LIP and 7a of the Macaque Journal ofNeuroscience 104 (1990) pp 1176-1196

54 B e Motter M A Steinmetz e J Duffy amp Mounrcastle VB Functional Properties of Partial Visual Neurons Mechanisms of Directionality Along a Single Axis Joumal of Neuroscience 71 (1987) pp 154-176

55 R A Andersen Visual and Eye Movement Functions of the Posterior Parietal Cortex Annual Reviews of Neuroscience 12 (1989) pp 377-403

56 P S Churchland V S Ramachandran amp T J Sejnowski A Critique of Pure Vision In Large-Scale Neuronal Theories of the Brain (e Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 23-61

57 H Suarex e Koch amp R Douglas Modeling Direction Selectivity of Simple Cells in Striate Visual Cortex Within the Framework of the Canonical Microcircuit Journal of Neuroscience 1510 (1995) pp 6700-6719

58 J W McClurkin L M Optican amp B J Richmond Cortical Feedback Increases Visual Information Transmitted by Monkey Parvocellular Lateral Geniculate Nucelus Neurons Visual Neuroscience 11 (1994) pp 601-617

59 A Gove S Grossberg amp E Mingolla Brightness Perception Illusory Contours and Corticogeniculate Feedback Visual Neuroscience 12 (1995) 1027-1052

60 H J Crawford amp J H Gruzelier A Midstream View of the Neuropsychophysiology of Hypnosis Recent Research and Future Directions In Contemporary Perspectives in Hypnosis Research (E Fromm amp M Nash Eds Guilford Press New York NY 1992) PI 227-266

Subtle Energies Energy Medicine bull Volume 7 bull Number 2 bull Page J47

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148

61 H J Crawford A M Brown amp C E Moon Sustained Anentional and Disattentional Abilities Differences Between Low and Highly Hypnotizable Persons Journal of Abnormal Psychology 1024 (1993) pp 534-543

62 R C Coghill ] D Talbot A C Evans E Meyer A Gjedde M C Bushnell amp G H Duncan Distributed Processing of Pain and Vibration by the Human Brain Journal of Neuroscience 147 (1994) pp 4095-4108

63 A K P Jones W D Brown K J Frisron L Y Qi amp R S J Frackowiack Cortical and Subcortical Location of Response to Pain in Man Using Positron Emission Tomography Proceedings of the Royal Society of London Series B Biological Sciences 244 (1991) pp 39-44

64 J D Talbot S Marrett A C Evans E Meyer M C Bushnell amp G H Duncan Multiple Representations of Pain in the Human Cerebral Cortex Science 251 (1991) pp 1355-1358

65 M Corbetta F M Miezin S Dobmeyer G L Shulman amp S E Petersen Selective and Divided Attention During Visual Discriminations of Shape Color and Speed Functional Anatomy by Positron Emission Tomography Journal ofNeuroscience 118 (1991) pp 2383-2402

66 M Corbetta F M Miezen G L Shulman amp S E Petersen A PET Study of Visuospatial Attention Journal ofNeuroscience 133 (1993) pp 1202-1226

67 M I Posner amp M K Rothbart Constructing Neuronal Theories of Mind In LargeshyScale Neuronal Theories of the Brain (c Koch amp J L Davis Eds MIT Press Cambridge MA 1994) pp 183-200

68 W C Drevers H Burton T O Videen A Z Snyder ] R Simpson amp M E Raichle Blood Flow Changes in Human Somatosensory Cortex During Anticipated Stimulation Nature 373 (1995) pp 249-252

69 F A Lenz M Seike Y C Lin F H Baker L H Rowland R H Gracely amp R T Richardson Neurons in the Area of the Human Thalamic Nucleus Ventralis Caudlis Respond to Painful Heat Stimuli Brain Research 623 (I993) pp 235-240

70 D Contreras amp M Steriade State-Dependent Fluctuations of Low-Frequency Rhythms in Cortico-Thalamic Networks Neuroscience 761 (1997) pp 25- 38

71 M Steriade D Contreras F Amzica amp I Timofeev Synchronization of Fast (30-40 Hz) Spontaneous Oscillations in Intrathalamic and Thalamocortical Networks Journal ofNeuroscience 168 (I 996) pp 2788-2808 also see D Contreras amp M Steriade StateshyDependent Fluctuations of Low-Frequency Rhythms in Corticothalamic Networks Neuroscience 761 (1997) pp 25-38

72 A Mavromatis Hypnagogia (Routledge amp Kegan Paul London 1987) 73 G M Edelman Neural Danvinism The Theory ofNeuronal Group Selection (Basic

Books New York NY 1987) 74 U Stabell amp B Stabell Mechanisms of Chromatic Rod Vision in Scotopic

Illumination Vision Research 348 (1993) pp 1019-1027

Subtle Energies amp Energy Medicine bull Volume 7 bull Number 2 bull Page 148